diff --git a/src/drivers/net/efi/mnpnet.c b/src/drivers/net/efi/mnpnet.c
index ead8691ff..902eb91f3 100644
--- a/src/drivers/net/efi/mnpnet.c
+++ b/src/drivers/net/efi/mnpnet.c
@@ -370,10 +370,6 @@ int mnpnet_start ( struct efi_device *efidev ) {
 	EFI_HANDLE device = efidev->device;
 	EFI_GUID *binding = &efi_managed_network_service_binding_protocol_guid;
 	EFI_SIMPLE_NETWORK_MODE mode;
-	union {
-		EFI_MANAGED_NETWORK_PROTOCOL *mnp;
-		void *interface;
-	} u;
 	struct net_device *netdev;
 	struct mnp_nic *mnp;
 	EFI_STATUS efirc;
@@ -409,12 +405,11 @@ int mnpnet_start ( struct efi_device *efidev ) {
 	/* Open MNP protocol */
 	if ( ( rc = efi_open_by_driver ( efidev->child,
 					 &efi_managed_network_protocol_guid,
-					 &u.interface ) ) != 0 ) {
+					 &mnp->mnp ) ) != 0 ) {
 		DBGC ( mnp, "MNP %s could not open MNP protocol: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		goto err_open;
 	}
-	mnp->mnp = u.mnp;
 
 	/* Get configuration */
 	efirc = mnp->mnp->GetModeData ( mnp->mnp, NULL, &mode );
diff --git a/src/drivers/net/efi/nii.c b/src/drivers/net/efi/nii.c
index 126584eff..81f1838a4 100644
--- a/src/drivers/net/efi/nii.c
+++ b/src/drivers/net/efi/nii.c
@@ -209,10 +209,6 @@ static int nii_pci_open ( struct nii_nic *nii ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE device = nii->efidev->device;
 	EFI_HANDLE pci_device;
-	union {
-		EFI_PCI_IO_PROTOCOL *pci_io;
-		void *interface;
-	} pci_io;
 	union {
 		EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *acpi;
 		void *resource;
@@ -237,12 +233,11 @@ static int nii_pci_open ( struct nii_nic *nii ) {
 	 * therefore use an unsafe open.
 	 */
 	if ( ( rc = efi_open_unsafe ( pci_device, &efi_pci_io_protocol_guid,
-				      &pci_io.interface ) ) != 0 ) {
+				      &nii->pci_io ) ) != 0 ) {
 		DBGC ( nii, "NII %s could not open PCI I/O protocol: %s\n",
 		       nii->dev.name, strerror ( rc ) );
 		goto err_open;
 	}
-	nii->pci_io = pci_io.pci_io;
 
 	/* Identify memory and I/O BARs */
 	nii->mem_bar = PCI_MAX_BAR;
@@ -1272,7 +1267,6 @@ int nii_start ( struct efi_device *efidev ) {
 	EFI_HANDLE device = efidev->device;
 	struct net_device *netdev;
 	struct nii_nic *nii;
-	void *interface;
 	int rc;
 
 	/* Allocate and initialise structure */
@@ -1298,13 +1292,12 @@ int nii_start ( struct efi_device *efidev ) {
 
 	/* Open NII protocol */
 	if ( ( rc = efi_open_by_driver ( device, &efi_nii31_protocol_guid,
-					 &interface ) ) != 0 ) {
+					 &nii->nii ) ) != 0 ) {
 		DBGC ( nii, "NII %s cannot open NII protocol: %s\n",
 		       nii->dev.name, strerror ( rc ) );
 		DBGC_EFI_OPENERS ( device, device, &efi_nii31_protocol_guid );
 		goto err_open_protocol;
 	}
-	nii->nii = interface;
 
 	/* Locate UNDI and entry point */
 	nii->undi = ( ( void * ) ( intptr_t ) nii->nii->Id );
diff --git a/src/drivers/net/efi/snpnet.c b/src/drivers/net/efi/snpnet.c
index 93ed8cd95..c8e2f2f68 100644
--- a/src/drivers/net/efi/snpnet.c
+++ b/src/drivers/net/efi/snpnet.c
@@ -504,7 +504,7 @@ int snpnet_supported ( EFI_HANDLE device, EFI_GUID *protocol ) {
 	}
 
 	/* Test for presence of protocol */
-	if ( ( rc = efi_open ( device, protocol, NULL ) ) != 0 ) {
+	if ( ( rc = efi_test ( device, protocol ) ) != 0 ) {
 		DBGCP ( device, "HANDLE %s is not a %s device\n",
 			efi_handle_name ( device ),
 			efi_guid_ntoa ( protocol ) );
@@ -536,10 +536,10 @@ int snpnet_supported ( EFI_HANDLE device, EFI_GUID *protocol ) {
  */
 int snpnet_start ( struct efi_device *efidev ) {
 	EFI_HANDLE device = efidev->device;
+	EFI_SIMPLE_NETWORK_PROTOCOL *interface;
 	EFI_SIMPLE_NETWORK_MODE *mode;
 	struct net_device *netdev;
 	struct snp_nic *snp;
-	void *interface;
 	EFI_STATUS efirc;
 	int rc;
 
diff --git a/src/drivers/usb/usbio.c b/src/drivers/usb/usbio.c
index db3beff21..73151c536 100644
--- a/src/drivers/usb/usbio.c
+++ b/src/drivers/usb/usbio.c
@@ -187,10 +187,6 @@ static int usbio_open ( struct usbio_device *usbio, unsigned int interface ) {
 	EFI_DEVICE_PATH_PROTOCOL *path;
 	EFI_DEVICE_PATH_PROTOCOL *end;
 	USB_DEVICE_PATH *usbpath;
-	union {
-		void *interface;
-		EFI_USB_IO_PROTOCOL *io;
-	} u;
 	EFI_STATUS efirc;
 	int rc;
 
@@ -231,7 +227,7 @@ static int usbio_open ( struct usbio_device *usbio, unsigned int interface ) {
 	/* Open USB I/O protocol on this handle */
 	if ( ( rc = efi_open_by_driver ( intf->handle,
 					 &efi_usb_io_protocol_guid,
-					 &u.interface ) ) != 0 ) {
+					 &intf->io ) ) != 0 ) {
 		DBGC ( usbio, "USBIO %s cannot open ",
 		       efi_handle_name ( handle ) );
 		DBGC ( usbio, "%s: %s\n",
@@ -240,7 +236,6 @@ static int usbio_open ( struct usbio_device *usbio, unsigned int interface ) {
 				   &efi_usb_io_protocol_guid );
 		return rc;
 	}
-	intf->io = u.io;
 
 	/* Increment usage count */
 	intf->count++;
@@ -1296,24 +1291,20 @@ static int usbio_supported ( EFI_HANDLE handle ) {
 	struct usb_function_descriptor desc;
 	struct usb_driver *driver;
 	struct usb_device_id *id;
-	union {
-		void *interface;
-		EFI_USB_IO_PROTOCOL *io;
-	} usb;
+	EFI_USB_IO_PROTOCOL *io;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Get protocol */
 	if ( ( rc = efi_open ( handle, &efi_usb_io_protocol_guid,
-			       &usb.interface ) ) != 0 ) {
+			       &io ) ) != 0 ) {
 		DBGCP ( handle, "USB %s is not a USB device\n",
 			efi_handle_name ( handle ) );
 		return rc;
 	}
 
 	/* Get device descriptor */
-	if ( ( efirc = usb.io->UsbGetDeviceDescriptor ( usb.io,
-							&device ) ) != 0 ) {
+	if ( ( efirc = io->UsbGetDeviceDescriptor ( io, &device ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( handle, "USB %s could not get device descriptor: "
 		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
@@ -1324,8 +1315,7 @@ static int usbio_supported ( EFI_HANDLE handle ) {
 	desc.product = device.IdProduct;
 
 	/* Get interface descriptor */
-	if ( ( efirc = usb.io->UsbGetInterfaceDescriptor ( usb.io,
-							   &interface ) ) !=0){
+	if ( ( efirc = io->UsbGetInterfaceDescriptor ( io, &interface ) ) != 0){
 		rc = -EEFI ( efirc );
 		DBGC ( handle, "USB %s could not get interface descriptor: "
 		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
@@ -1460,21 +1450,16 @@ static int usbio_path ( struct usbio_device *usbio ) {
 	EFI_DEVICE_PATH_PROTOCOL *path;
 	EFI_DEVICE_PATH_PROTOCOL *end;
 	USB_DEVICE_PATH *usbpath;
-	union {
-		void *interface;
-		EFI_DEVICE_PATH_PROTOCOL *path;
-	} u;
 	size_t len;
 	int rc;
 
 	/* Open device path protocol */
 	if ( ( rc = efi_open ( handle, &efi_device_path_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &path ) ) != 0 ) {
 		DBGC ( usbio, "USBIO %s cannot open device path protocol: "
 		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
 		return rc;
 	}
-	path = u.interface;
 
 	/* Locate end of device path and sanity check */
 	len = efi_path_len ( path );
@@ -1567,10 +1552,6 @@ static int usbio_start ( struct efi_device *efidev ) {
 	EFI_HANDLE handle = efidev->device;
 	struct usbio_device *usbio;
 	struct usb_port *port;
-	union {
-		void *interface;
-		EFI_USB_IO_PROTOCOL *io;
-	} u;
 	int rc;
 
 	/* Allocate and initialise structure */
@@ -1585,13 +1566,12 @@ static int usbio_start ( struct efi_device *efidev ) {
 
 	/* Open USB I/O protocol */
 	if ( ( rc = efi_open_by_driver ( handle, &efi_usb_io_protocol_guid,
-					 &u.interface ) ) != 0 ) {
+					 &usbio->io ) ) != 0 ) {
 		DBGC ( usbio, "USBIO %s cannot open USB I/O protocol: %s\n",
 		       efi_handle_name ( handle ), strerror ( rc ) );
 		DBGC_EFI_OPENERS ( usbio, handle, &efi_usb_io_protocol_guid );
 		goto err_open_usbio;
 	}
-	usbio->io = u.io;
 
 	/* Describe generic device */
 	efi_device_info ( handle, "USB", &usbio->dev );
diff --git a/src/image/efi_image.c b/src/image/efi_image.c
index ae9255ce5..82101d484 100644
--- a/src/image/efi_image.c
+++ b/src/image/efi_image.c
@@ -132,10 +132,7 @@ static int efi_image_exec ( struct image *image ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	struct efi_snp_device *snpdev;
 	EFI_DEVICE_PATH_PROTOCOL *path;
-	union {
-		EFI_LOADED_IMAGE_PROTOCOL *image;
-		void *interface;
-	} loaded;
+	EFI_LOADED_IMAGE_PROTOCOL *loaded;
 	struct image *shim;
 	struct image *exec;
 	EFI_HANDLE handle;
@@ -235,30 +232,30 @@ static int efi_image_exec ( struct image *image ) {
 
 	/* Get the loaded image protocol for the newly loaded image */
 	if ( ( rc = efi_open (  handle, &efi_loaded_image_protocol_guid,
-				&loaded.interface ) ) != 0 ) {
+				&loaded ) ) != 0 ) {
 		/* Should never happen */
 		goto err_open_protocol;
 	}
 
 	/* Some EFI 1.10 implementations seem not to fill in DeviceHandle */
-	if ( loaded.image->DeviceHandle == NULL ) {
+	if ( loaded->DeviceHandle == NULL ) {
 		DBGC ( image, "EFIIMAGE %s filling in missing DeviceHandle\n",
 		       image->name );
-		loaded.image->DeviceHandle = snpdev->handle;
+		loaded->DeviceHandle = snpdev->handle;
 	}
 
 	/* Sanity checks */
-	assert ( loaded.image->ParentHandle == efi_image_handle );
-	assert ( loaded.image->DeviceHandle == snpdev->handle );
-	assert ( loaded.image->LoadOptionsSize == 0 );
-	assert ( loaded.image->LoadOptions == NULL );
+	assert ( loaded->ParentHandle == efi_image_handle );
+	assert ( loaded->DeviceHandle == snpdev->handle );
+	assert ( loaded->LoadOptionsSize == 0 );
+	assert ( loaded->LoadOptions == NULL );
 
 	/* Record image code type */
-	type = loaded.image->ImageCodeType;
+	type = loaded->ImageCodeType;
 
 	/* Set command line */
-	loaded.image->LoadOptions = cmdline;
-	loaded.image->LoadOptionsSize =
+	loaded->LoadOptions = cmdline;
+	loaded->LoadOptionsSize =
 		( ( wcslen ( cmdline ) + 1 /* NUL */ ) * sizeof ( wchar_t ) );
 
 	/* Release network devices for use via SNP */
diff --git a/src/include/ipxe/efi/efi.h b/src/include/ipxe/efi/efi.h
index 6126d3b87..5fae87731 100644
--- a/src/include/ipxe/efi/efi.h
+++ b/src/include/ipxe/efi/efi.h
@@ -389,17 +389,88 @@ extern EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 			     EFI_SYSTEM_TABLE *systab );
 extern void efi_raise_tpl ( struct efi_saved_tpl *tpl );
 extern void efi_restore_tpl ( struct efi_saved_tpl *tpl );
-extern int efi_open ( EFI_HANDLE handle, EFI_GUID *protocol,
-		      void **interface );
-extern int efi_open_unsafe ( EFI_HANDLE handle, EFI_GUID *protocol,
-			     void **interface );
+extern int efi_open_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+			      void **interface );
+extern int efi_open_unsafe_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+				     void **interface );
 extern void efi_close_unsafe ( EFI_HANDLE handle, EFI_GUID *protocol );
-extern int efi_open_by_driver ( EFI_HANDLE handle, EFI_GUID *protocol,
-				void **interface );
+extern int efi_open_by_driver_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+					void **interface );
 extern void efi_close_by_driver ( EFI_HANDLE handle, EFI_GUID *protocol );
-extern int efi_open_by_child ( EFI_HANDLE handle, EFI_GUID *protocol,
-			       EFI_HANDLE child, void **interface );
+extern int efi_open_by_child_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+				       EFI_HANDLE child, void **interface );
 extern void efi_close_by_child ( EFI_HANDLE handle, EFI_GUID *protocol,
 				 EFI_HANDLE child );
 
+/**
+ * Test protocol existence
+ *
+ * @v handle		EFI handle
+ * @v protocol		Protocol GUID
+ * @ret rc		Return status code
+ */
+#define efi_test( handle, protocol )					\
+	efi_open_untyped ( (handle), (protocol), NULL )
+
+/**
+ * Open protocol for ephemeral use
+ *
+ * @v handle		EFI handle
+ * @v protocol		Protocol GUID
+ * @v interface		Protocol interface pointer to fill in
+ * @ret rc		Return status code
+ */
+#define efi_open( handle, protocol, interface ) ( {			\
+	typeof ( *(interface) ) check_ptr_ptr = NULL;			\
+	efi_open_untyped ( (handle), (protocol),			\
+			   ( ( void ) check_ptr_ptr,			\
+			     ( void ** ) (interface) ) );		\
+	} )
+
+/**
+ * Open protocol for unsafe persistent use
+ *
+ * @v handle		EFI handle
+ * @v protocol		Protocol GUID
+ * @v interface		Protocol interface pointer to fill in
+ * @ret rc		Return status code
+ */
+#define efi_open_unsafe( handle, protocol, interface ) ( {		\
+	typeof ( *(interface) ) check_ptr_ptr = NULL;			\
+	efi_open_unsafe_untyped ( (handle), (protocol),			\
+				  ( ( void ) check_ptr_ptr,		\
+				    ( void ** ) (interface) ) );	\
+	} )
+
+/**
+ * Open protocol for persistent use by a driver
+ *
+ * @v handle		EFI handle
+ * @v protocol		Protocol GUID
+ * @v interface		Protocol interface pointer to fill in
+ * @ret rc		Return status code
+ */
+#define efi_open_by_driver( handle, protocol, interface ) ( {		\
+	typeof ( *(interface) ) check_ptr_ptr = NULL;			\
+	efi_open_by_driver_untyped ( (handle), (protocol),		\
+				     ( ( void ) check_ptr_ptr,		\
+				       ( void ** ) (interface) ) );	\
+	} )
+
+/**
+ * Open protocol for persistent use by a child controller
+ *
+ * @v handle		EFI handle
+ * @v protocol		Protocol GUID
+ * @v child		Child controller handle
+ * @v interface		Protocol interface pointer to fill in
+ * @ret rc		Return status code
+ */
+#define efi_open_by_child( handle, protocol, child, interface ) ( {	\
+	typeof ( *(interface) ) check_ptr_ptr = NULL;			\
+	efi_open_by_child_untyped ( (handle), (protocol), (child),	\
+				    ( ( void ) check_ptr_ptr,		\
+				      ( void ** ) (interface) ) );	\
+	} )
+
 #endif /* _IPXE_EFI_H */
diff --git a/src/interface/efi/efi_autoboot.c b/src/interface/efi/efi_autoboot.c
index 528b84f1e..e52c857d8 100644
--- a/src/interface/efi/efi_autoboot.c
+++ b/src/interface/efi/efi_autoboot.c
@@ -48,24 +48,21 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  */
 int efi_set_autoboot_ll_addr ( EFI_HANDLE device,
 			       EFI_DEVICE_PATH_PROTOCOL *path ) {
-	union {
-		EFI_SIMPLE_NETWORK_PROTOCOL *snp;
-		void *interface;
-	} snp;
+	EFI_SIMPLE_NETWORK_PROTOCOL *snp;
 	EFI_SIMPLE_NETWORK_MODE *mode;
 	unsigned int vlan;
 	int rc;
 
 	/* Look for an SNP instance on the image's device handle */
 	if ( ( rc = efi_open ( device, &efi_simple_network_protocol_guid,
-			       &snp.interface ) ) != 0 ) {
+			       &snp ) ) != 0 ) {
 		DBGC ( device, "EFI %s has no SNP instance: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		return rc;
 	}
 
 	/* Record autoboot device */
-	mode = snp.snp->Mode;
+	mode = snp->Mode;
 	vlan = efi_path_vlan ( path );
 	set_autoboot_ll_addr ( &mode->CurrentAddress, mode->HwAddressSize,
 			       vlan );
diff --git a/src/interface/efi/efi_block.c b/src/interface/efi/efi_block.c
index 34b73c265..5165bd804 100644
--- a/src/interface/efi/efi_block.c
+++ b/src/interface/efi/efi_block.c
@@ -518,23 +518,20 @@ static int efi_block_describe ( void ) {
  */
 static int efi_block_root ( unsigned int drive, EFI_HANDLE handle,
 			    EFI_FILE_PROTOCOL **root ) {
-	union {
-		EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
-		void *interface;
-	} u;
+	EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Open filesystem protocol */
 	if ( ( rc = efi_open ( handle, &efi_simple_file_system_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &fs ) ) != 0 ) {
 		DBGC ( drive, "EFIBLK %#02x could not open %s filesystem: %s\n",
 		       drive, efi_handle_name ( handle ), strerror ( rc ) );
 		return rc;
 	}
 
 	/* Open root volume */
-	if ( ( efirc = u.fs->OpenVolume ( u.fs, root ) ) != 0 ) {
+	if ( ( efirc = fs->OpenVolume ( fs, root ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( drive, "EFIBLK %#02x could not open %s root: %s\n",
 		       drive, efi_handle_name ( handle ), strerror ( rc ) );
@@ -664,26 +661,21 @@ static int efi_block_match ( unsigned int drive, EFI_HANDLE handle,
 			     EFI_DEVICE_PATH_PROTOCOL *path,
 			     struct san_boot_config *config,
 			     EFI_DEVICE_PATH_PROTOCOL **fspath ) {
-	union {
-		EFI_DEVICE_PATH_PROTOCOL *path;
-		void *interface;
-	} u;
 	EFI_FILE *root;
 	union uuid guid;
 	int rc;
 
 	/* Identify device path */
 	if ( ( rc = efi_open ( handle, &efi_device_path_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       fspath ) ) != 0 ) {
 		DBGC ( drive, "EFIBLK %#02x could not open %s device path: "
 		       "%s\n", drive, efi_handle_name ( handle ),
 		       strerror ( rc ) );
 		goto err_open;
 	}
-	*fspath = u.path;
 
 	/* Check if filesystem is a child of this block device */
-	if ( memcmp ( u.path, path, efi_path_len ( path ) ) != 0 ) {
+	if ( memcmp ( *fspath, path, efi_path_len ( path ) ) != 0 ) {
 		/* Not a child device */
 		rc = -ENOTTY;
 		DBGC2 ( drive, "EFIBLK %#02x is not parent of %s\n",
@@ -691,11 +683,11 @@ static int efi_block_match ( unsigned int drive, EFI_HANDLE handle,
 		goto err_not_child;
 	}
 	DBGC ( drive, "EFIBLK %#02x contains filesystem %s\n",
-	       drive, efi_devpath_text ( u.path ) );
+	       drive, efi_devpath_text ( *fspath ) );
 
 	/* Check if filesystem matches GUID, if applicable */
 	if ( config->uuid ) {
-		if ( ( rc = efi_path_guid ( u.path, &guid ) ) != 0 ) {
+		if ( ( rc = efi_path_guid ( *fspath, &guid ) ) != 0 ) {
 			DBGC ( drive, "EFIBLK %#02x could not determine GUID: "
 			       "%s\n", drive, strerror ( rc ) );
 			goto err_no_guid;
@@ -760,10 +752,7 @@ static int efi_block_scan ( unsigned int drive, EFI_HANDLE handle,
 			    struct san_boot_config *config,
 			    EFI_DEVICE_PATH_PROTOCOL **fspath ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_DEVICE_PATH_PROTOCOL *path;
-		void *interface;
-	} u;
+	EFI_DEVICE_PATH_PROTOCOL *path;
 	EFI_HANDLE *handles;
 	UINTN count;
 	unsigned int i;
@@ -775,7 +764,7 @@ static int efi_block_scan ( unsigned int drive, EFI_HANDLE handle,
 
 	/* Identify device path */
 	if ( ( rc = efi_open ( handle, &efi_device_path_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &path ) ) != 0 ) {
 		DBGC ( drive, "EFIBLK %#02x could not open device path: %s\n",
 		       drive, strerror ( rc ) );
 		goto err_open;
@@ -796,7 +785,7 @@ static int efi_block_scan ( unsigned int drive, EFI_HANDLE handle,
 	for ( i = 0 ; i < count ; i++ ) {
 
 		/* Check for a matching filesystem */
-		if ( ( rc = efi_block_match ( drive, handles[i], u.path,
+		if ( ( rc = efi_block_match ( drive, handles[i], path,
 					      config, fspath ) ) != 0 )
 			continue;
 
@@ -903,10 +892,7 @@ static int efi_block_exec ( unsigned int drive,
 static int efi_block_local ( EFI_HANDLE handle ) {
 	struct san_device *sandev;
 	struct efi_block_data *block;
-	union {
-		EFI_BLOCK_IO_PROTOCOL *blockio;
-		void *interface;
-	} u;
+	EFI_BLOCK_IO_PROTOCOL *blockio;
 	int rc;
 
 	/* Check if handle belongs to a SAN device */
@@ -918,14 +904,14 @@ static int efi_block_local ( EFI_HANDLE handle ) {
 
 	/* Open block I/O protocol */
 	if ( ( rc = efi_open ( handle, &efi_block_io_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &blockio ) ) != 0 ) {
 		DBGC ( handle, "EFIBLK %s could not open block I/O: %s\n",
 		       efi_handle_name ( handle ), strerror ( rc ) );
 		return rc;
 	}
 
 	/* Do not assign drive numbers for partitions */
-	if ( u.blockio->Media->LogicalPartition ) {
+	if ( blockio->Media->LogicalPartition ) {
 		DBGC2 ( handle, "EFLBLK %s is a partition\n",
 			efi_handle_name ( handle ) );
 		return -ENOTTY;
diff --git a/src/interface/efi/efi_bofm.c b/src/interface/efi/efi_bofm.c
index 6d97ff445..b64770d8a 100644
--- a/src/interface/efi/efi_bofm.c
+++ b/src/interface/efi/efi_bofm.c
@@ -228,7 +228,6 @@ static int efi_bofm_start ( struct efi_device *efidev ) {
 	struct efi_pci_device efipci;
 	IBM_BOFM_TABLE *bofmtab;
 	IBM_BOFM_TABLE *bofmtab2;
-	void *pci_io;
 	int bofmrc;
 	EFI_STATUS efirc;
 	int rc;
@@ -242,7 +241,7 @@ static int efi_bofm_start ( struct efi_device *efidev ) {
 
 	/* Open PCI I/O protocol */
 	if ( ( rc = efi_open_unsafe ( device, &efi_pci_io_protocol_guid,
-				      &pci_io ) ) != 0 ) {
+				      &efipci.io ) ) != 0 ) {
 		DBGC ( device, "EFIBOFM %s cannot open PCI device: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		goto err_open;
diff --git a/src/interface/efi/efi_cachedhcp.c b/src/interface/efi/efi_cachedhcp.c
index 68671d7c6..eb41a8e43 100644
--- a/src/interface/efi/efi_cachedhcp.c
+++ b/src/interface/efi/efi_cachedhcp.c
@@ -47,10 +47,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 int efi_cachedhcp_record ( EFI_HANDLE device,
 			   EFI_DEVICE_PATH_PROTOCOL *path ) {
 	unsigned int vlan;
-	union {
-		EFI_PXE_BASE_CODE_PROTOCOL *pxe;
-		void *interface;
-	} pxe;
+	EFI_PXE_BASE_CODE_PROTOCOL *pxe;
 	EFI_PXE_BASE_CODE_MODE *mode;
 	int rc;
 
@@ -59,14 +56,14 @@ int efi_cachedhcp_record ( EFI_HANDLE device,
 
 	/* Look for a PXE base code instance on the image's device handle */
 	if ( ( rc = efi_open ( device, &efi_pxe_base_code_protocol_guid,
-			       &pxe.interface ) ) != 0 ) {
+			       &pxe ) ) != 0 ) {
 		DBGC ( device, "EFI %s has no PXE base code instance: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		return rc;
 	}
 
 	/* Do not attempt to cache IPv6 packets */
-	mode = pxe.pxe->Mode;
+	mode = pxe->Mode;
 	if ( mode->UsingIpv6 ) {
 		DBGC ( device, "EFI %s has IPv6 PXE base code\n",
 		       efi_handle_name ( device ) );
diff --git a/src/interface/efi/efi_console.c b/src/interface/efi/efi_console.c
index 41c4dcf2c..9fc3c65c0 100644
--- a/src/interface/efi/efi_console.c
+++ b/src/interface/efi/efi_console.c
@@ -416,10 +416,6 @@ struct console_driver efi_console __console_driver = {
  */
 static void efi_console_init ( void ) {
 	EFI_CONSOLE_CONTROL_SCREEN_MODE mode;
-	union {
-		void *interface;
-		EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL *wtf;
-	} u;
 	int rc;
 
 	/* On some older EFI 1.10 implementations, we must use the
@@ -441,8 +437,7 @@ static void efi_console_init ( void ) {
 	 */
 	if ( ( rc = efi_open_unsafe ( efi_systab->ConsoleInHandle,
 				      &efi_simple_text_input_ex_protocol_guid,
-				      &u.interface ) ) == 0 ) {
-		efi_conin_ex = u.wtf;
+				      &efi_conin_ex ) ) == 0 ) {
 		DBG ( "EFI using SimpleTextInputEx\n" );
 	} else {
 		DBG ( "EFI has no SimpleTextInputEx: %s\n", strerror ( rc ) );
diff --git a/src/interface/efi/efi_debug.c b/src/interface/efi/efi_debug.c
index fd4997ccc..026adc25e 100644
--- a/src/interface/efi/efi_debug.c
+++ b/src/interface/efi/efi_debug.c
@@ -324,10 +324,7 @@ static const char * efi_driver_name2 ( EFI_COMPONENT_NAME2_PROTOCOL *wtf ) {
  * @ret name		Driver name, or NULL
  */
 static const char * efi_binding_name ( EFI_DRIVER_BINDING_PROTOCOL *binding ) {
-	union {
-		EFI_COMPONENT_NAME_PROTOCOL *name;
-		void *interface;
-	} u;
+	EFI_COMPONENT_NAME_PROTOCOL *name;
 	EFI_HANDLE image;
 	int rc;
 
@@ -340,13 +337,13 @@ static const char * efi_binding_name ( EFI_DRIVER_BINDING_PROTOCOL *binding ) {
 	/* Try to open component name protocol on image handle */
 	image = binding->ImageHandle;
 	if ( ( rc = efi_open ( image, &efi_component_name_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &name ) ) != 0 ) {
 		DBG ( "[DriverBinding no ComponentName]" );
 		return NULL;
 	}
 
 	/* Try to get name from component name protocol */
-	return efi_driver_name ( u.name );
+	return efi_driver_name ( name );
 }
 
 /**
@@ -357,10 +354,7 @@ static const char * efi_binding_name ( EFI_DRIVER_BINDING_PROTOCOL *binding ) {
  */
 static const char * efi_binding_name2 ( EFI_DRIVER_BINDING_PROTOCOL *binding ){
 	EFI_HANDLE image;
-	union {
-		EFI_COMPONENT_NAME2_PROTOCOL *name2;
-		void *interface;
-	} u;
+	EFI_COMPONENT_NAME2_PROTOCOL *name2;
 	int rc;
 
 	/* Sanity check */
@@ -372,13 +366,13 @@ static const char * efi_binding_name2 ( EFI_DRIVER_BINDING_PROTOCOL *binding ){
 	/* Try to open component name protocol on image handle */
 	image = binding->ImageHandle;
 	if ( ( rc = efi_open ( image, &efi_component_name2_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &name2 ) ) != 0 ) {
 		DBG ( "[DriverBinding no ComponentName2]" );
 		return NULL;
 	}
 
 	/* Try to get name from component name protocol */
-	return efi_driver_name2 ( u.name2 );
+	return efi_driver_name2 ( name2 );
 }
 
 /**
diff --git a/src/interface/efi/efi_driver.c b/src/interface/efi/efi_driver.c
index d143249ca..56918deba 100644
--- a/src/interface/efi/efi_driver.c
+++ b/src/interface/efi/efi_driver.c
@@ -69,22 +69,19 @@ static int efi_driver_disconnecting;
  */
 struct efi_device * efidev_alloc ( EFI_HANDLE device ) {
 	struct efi_device *efidev = NULL;
-	union {
-		EFI_DEVICE_PATH_PROTOCOL *path;
-		void *interface;
-	} path;
+	EFI_DEVICE_PATH_PROTOCOL *path;
 	EFI_DEVICE_PATH_PROTOCOL *path_end;
 	size_t path_len;
 	int rc;
 
 	/* Open device path */
 	if ( ( rc = efi_open ( device, &efi_device_path_protocol_guid,
-			       &path.interface ) ) != 0 ) {
+			       &path ) ) != 0 ) {
 		DBGC ( device, "EFIDRV %s could not open device path: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		return NULL;
 	}
-	path_len = ( efi_path_len ( path.path ) + sizeof ( *path_end ) );
+	path_len = ( efi_path_len ( path ) + sizeof ( *path_end ) );
 
 	/* Allocate and initialise structure */
 	efidev = zalloc ( sizeof ( *efidev ) + path_len );
@@ -93,7 +90,7 @@ struct efi_device * efidev_alloc ( EFI_HANDLE device ) {
 	efidev->device = device;
 	efidev->dev.desc.bus_type = BUS_TYPE_EFI;
 	efidev->path = ( ( ( void * ) efidev ) + sizeof ( *efidev ) );
-	memcpy ( efidev->path, path.path, path_len );
+	memcpy ( efidev->path, path, path_len );
 	INIT_LIST_HEAD ( &efidev->dev.children );
 	list_add ( &efidev->dev.siblings, &efi_devices );
 
@@ -365,10 +362,7 @@ static EFI_STATUS EFIAPI
 efi_driver_controller_name ( EFI_COMPONENT_NAME2_PROTOCOL *wtf __unused,
 			     EFI_HANDLE device, EFI_HANDLE child,
 			     CHAR8 *language, CHAR16 **controller_name ) {
-	union {
-		EFI_COMPONENT_NAME2_PROTOCOL *name2;
-		void *interface;
-	} name2;
+	EFI_COMPONENT_NAME2_PROTOCOL *name2;
 	int rc;
 
 	/* Delegate to the EFI_COMPONENT_NAME2_PROTOCOL instance
@@ -376,10 +370,9 @@ efi_driver_controller_name ( EFI_COMPONENT_NAME2_PROTOCOL *wtf __unused,
 	 */
 	if ( ( child != NULL ) &&
 	     ( ( rc = efi_open ( child, &efi_component_name2_protocol_guid,
-				 &name2.interface ) ) == 0 ) ) {
-		return name2.name2->GetControllerName ( name2.name2, device,
-							child, language,
-							controller_name );
+				 &name2 ) ) == 0 ) ) {
+		return name2->GetControllerName ( name2, device, child,
+						  language, controller_name );
 	}
 
 	/* Otherwise, let EFI use the default Device Path Name */
diff --git a/src/interface/efi/efi_file.c b/src/interface/efi/efi_file.c
index d8b9f819c..b7b97aee7 100644
--- a/src/interface/efi/efi_file.c
+++ b/src/interface/efi/efi_file.c
@@ -982,9 +982,9 @@ static EFI_DISK_IO_PROTOCOL efi_disk_io_protocol = {
  */
 static int efi_file_path_claim ( struct efi_file_path *file ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
+	EFI_DEVICE_PATH_PROTOCOL *old;
 	EFI_DEVICE_PATH_PROTOCOL *end;
 	EFI_HANDLE handle;
-	VOID *old;
 	EFI_STATUS efirc;
 	int rc;
 
@@ -1116,10 +1116,7 @@ static void efi_file_path_uninstall ( struct efi_file_path *file ) {
  */
 int efi_file_install ( EFI_HANDLE handle ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_DISK_IO_PROTOCOL *diskio;
-		void *interface;
-	} diskio;
+	EFI_DISK_IO_PROTOCOL *diskio;
 	struct image *image;
 	EFI_STATUS efirc;
 	int rc;
@@ -1168,13 +1165,13 @@ int efi_file_install ( EFI_HANDLE handle ) {
 	 * shell.  I have no idea why this is.
 	 */
 	if ( ( rc = efi_open_by_driver ( handle, &efi_disk_io_protocol_guid,
-					 &diskio.interface ) ) != 0 ) {
+					 &diskio ) ) != 0 ) {
 		DBGC ( handle, "Could not open disk I/O protocol: %s\n",
 		       strerror ( rc ) );
 		DBGC_EFI_OPENERS ( handle, handle, &efi_disk_io_protocol_guid );
 		goto err_open;
 	}
-	assert ( diskio.diskio == &efi_disk_io_protocol );
+	assert ( diskio == &efi_disk_io_protocol );
 
 	/* Claim Linux initrd fixed device path */
 	if ( ( rc = efi_file_path_claim ( &efi_file_initrd ) ) != 0 )
diff --git a/src/interface/efi/efi_init.c b/src/interface/efi/efi_init.c
index 03506ec5c..1ba144ee7 100644
--- a/src/interface/efi/efi_init.c
+++ b/src/interface/efi/efi_init.c
@@ -173,8 +173,7 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 	EFI_BOOT_SERVICES *bs;
 	struct efi_protocol *prot;
 	struct efi_config_table *tab;
-	void *loaded_image;
-	void *device_path;
+	EFI_DEVICE_PATH_PROTOCOL *device_path;
 	void *device_path_copy;
 	size_t device_path_len;
 	EFI_STATUS efirc;
@@ -248,13 +247,12 @@ EFI_STATUS efi_init ( EFI_HANDLE image_handle,
 	 */
 	if ( ( rc = efi_open_unsafe ( image_handle,
 				      &efi_loaded_image_protocol_guid,
-				      &loaded_image ) ) != 0 ) {
+				      &efi_loaded_image ) ) != 0 ) {
 		DBGC ( systab, "EFI could not get loaded image protocol: %s",
 		       strerror ( rc ) );
 		efirc = EFIRC ( rc );
 		goto err_no_loaded_image;
 	}
-	efi_loaded_image = loaded_image;
 	DBGC ( systab, "EFI image base address %p\n",
 	       efi_loaded_image->ImageBase );
 
diff --git a/src/interface/efi/efi_local.c b/src/interface/efi/efi_local.c
index 80cfb5a22..4564470fc 100644
--- a/src/interface/efi/efi_local.c
+++ b/src/interface/efi/efi_local.c
@@ -208,23 +208,20 @@ static int efi_local_check_volume_name ( struct efi_local *local,
  */
 static int efi_local_open_root ( struct efi_local *local, EFI_HANDLE device,
 				 EFI_FILE_PROTOCOL **root ) {
-	union {
-		void *interface;
-		EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
-	} u;
+	EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Open file system protocol */
 	if ( ( rc = efi_open ( device, &efi_simple_file_system_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &fs ) ) != 0 ) {
 		DBGC ( local, "LOCAL %p could not open filesystem on %s: %s\n",
 		       local, efi_handle_name ( device ), strerror ( rc ) );
 		return rc;
 	}
 
 	/* Open root directory */
-	if ( ( efirc = u.fs->OpenVolume ( u.fs, root ) ) != 0 ) {
+	if ( ( efirc = fs->OpenVolume ( fs, root ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( local, "LOCAL %p could not open volume on %s: %s\n",
 		       local, efi_handle_name ( device ), strerror ( rc ) );
diff --git a/src/interface/efi/efi_open.c b/src/interface/efi/efi_open.c
index c85c027e1..8f8af4ea0 100644
--- a/src/interface/efi/efi_open.c
+++ b/src/interface/efi/efi_open.c
@@ -93,7 +93,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  * @v interface		Protocol interface pointer to fill in (or NULL to test)
  * @ret rc		Return status code
  */
-int efi_open ( EFI_HANDLE handle, EFI_GUID *protocol, void **interface ) {
+int efi_open_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+		       void **interface ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE agent = efi_image_handle;
 	EFI_HANDLE controller;
@@ -176,8 +177,8 @@ int efi_open ( EFI_HANDLE handle, EFI_GUID *protocol, void **interface ) {
  * @v interface		Protocol interface pointer to fill in
  * @ret rc		Return status code
  */
-int efi_open_unsafe ( EFI_HANDLE handle, EFI_GUID *protocol,
-		      void **interface ) {
+int efi_open_unsafe_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+			      void **interface ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE agent = efi_image_handle;
 	EFI_HANDLE controller;
@@ -236,8 +237,8 @@ void efi_close_unsafe ( EFI_HANDLE handle, EFI_GUID *protocol ) {
  * @v interface		Protocol interface pointer to fill in
  * @ret rc		Return status code
  */
-int efi_open_by_driver ( EFI_HANDLE handle, EFI_GUID *protocol,
-			 void **interface ) {
+int efi_open_by_driver_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+				 void **interface ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE agent = efi_image_handle;
 	EFI_HANDLE controller;
@@ -297,8 +298,8 @@ void efi_close_by_driver ( EFI_HANDLE handle, EFI_GUID *protocol ) {
  * @v interface		Protocol interface pointer to fill in
  * @ret rc		Return status code
  */
-int efi_open_by_child ( EFI_HANDLE handle, EFI_GUID *protocol,
-			EFI_HANDLE child, void **interface ) {
+int efi_open_by_child_untyped ( EFI_HANDLE handle, EFI_GUID *protocol,
+				EFI_HANDLE child, void **interface ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE agent = efi_image_handle;
 	EFI_HANDLE controller;
diff --git a/src/interface/efi/efi_pci.c b/src/interface/efi/efi_pci.c
index 003fa2f4a..0662302d2 100644
--- a/src/interface/efi/efi_pci.c
+++ b/src/interface/efi/efi_pci.c
@@ -72,10 +72,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  */
 static int efipci_discover_one ( struct pci_device *pci, EFI_HANDLE handle,
 				 struct pci_range *range ) {
-	union {
-		void *interface;
-		EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *root;
-	} root;
+	EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *root;
 	union {
 		union acpi_resource *res;
 		void *raw;
@@ -94,7 +91,7 @@ static int efipci_discover_one ( struct pci_device *pci, EFI_HANDLE handle,
 
 	/* Open root bridge I/O protocol */
 	if ( ( rc = efi_open ( handle, &efi_pci_root_bridge_io_protocol_guid,
-			       &root.interface ) ) != 0 ) {
+			       &root ) ) != 0 ) {
 		DBGC ( pci, "EFIPCI " PCI_FMT " cannot open %s: %s\n",
 		       PCI_ARGS ( pci ), efi_handle_name ( handle ),
 		       strerror ( rc ) );
@@ -102,8 +99,7 @@ static int efipci_discover_one ( struct pci_device *pci, EFI_HANDLE handle,
 	}
 
 	/* Get ACPI resource descriptors */
-	if ( ( efirc = root.root->Configuration ( root.root,
-						  &acpi.raw ) ) != 0 ) {
+	if ( ( efirc = root->Configuration ( root, &acpi.raw ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( pci, "EFIPCI " PCI_FMT " cannot get configuration for "
 		       "%s: %s\n", PCI_ARGS ( pci ),
@@ -123,13 +119,13 @@ static int efipci_discover_one ( struct pci_device *pci, EFI_HANDLE handle,
 			continue;
 
 		/* Get range for this descriptor */
-		start = PCI_BUSDEVFN ( root.root->SegmentNumber,
+		start = PCI_BUSDEVFN ( root->SegmentNumber,
 				       le64_to_cpu ( acpi.res->qword.min ),
 				       0, 0 );
 		count = PCI_BUSDEVFN ( 0, le64_to_cpu ( acpi.res->qword.len ),
 				       0, 0 );
 		DBGC2 ( pci, "EFIPCI " PCI_FMT " found %04x:[%02x-%02x] via "
-			"%s\n", PCI_ARGS ( pci ), root.root->SegmentNumber,
+			"%s\n", PCI_ARGS ( pci ), root->SegmentNumber,
 			PCI_BUS ( start ), PCI_BUS ( start + count - 1 ),
 			efi_handle_name ( handle ) );
 
@@ -150,8 +146,7 @@ static int efipci_discover_one ( struct pci_device *pci, EFI_HANDLE handle,
 	 * bridge has a single bus.
 	 */
 	if ( ! range->count ) {
-		range->start = PCI_BUSDEVFN ( root.root->SegmentNumber,
-					      0, 0, 0 );
+		range->start = PCI_BUSDEVFN ( root->SegmentNumber, 0, 0, 0 );
 		range->count = PCI_BUSDEVFN ( 0, 1, 0, 0 );
 	}
 
@@ -259,10 +254,6 @@ static void efipci_discover ( uint32_t busdevfn, struct pci_range *range ) {
 static int efipci_root_open ( struct pci_device *pci, EFI_HANDLE *handle,
 			      EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL **root ) {
 	struct pci_range tmp;
-	union {
-		void *interface;
-		EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *root;
-	} u;
 	int rc;
 
 	/* Find matching root bridge I/O protocol handle */
@@ -271,16 +262,13 @@ static int efipci_root_open ( struct pci_device *pci, EFI_HANDLE *handle,
 
 	/* Open PCI root bridge I/O protocol */
 	if ( ( rc = efi_open ( *handle, &efi_pci_root_bridge_io_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       root ) ) != 0 ) {
 		DBGC ( pci, "EFIPCI " PCI_FMT " cannot open %s: %s\n",
 		       PCI_ARGS ( pci ), efi_handle_name ( *handle ),
 		       strerror ( rc ) );
 		return rc;
 	}
 
-	/* Return opened protocol */
-	*root = u.root;
-
 	return 0;
 }
 
@@ -742,10 +730,7 @@ static struct dma_operations efipci_dma_operations = {
  * @ret rc		Return status code
  */
 int efipci_info ( EFI_HANDLE device, struct efi_pci_device *efipci ) {
-	union {
-		EFI_PCI_IO_PROTOCOL *pci_io;
-		void *interface;
-	} pci_io;
+	EFI_PCI_IO_PROTOCOL *pci_io;
 	UINTN pci_segment, pci_bus, pci_dev, pci_fn;
 	unsigned int busdevfn;
 	EFI_STATUS efirc;
@@ -753,17 +738,16 @@ int efipci_info ( EFI_HANDLE device, struct efi_pci_device *efipci ) {
 
 	/* See if device is a PCI device */
 	if ( ( rc = efi_open ( device, &efi_pci_io_protocol_guid,
-			       &pci_io.interface ) ) != 0 ) {
+			       &pci_io ) ) != 0 ) {
 		DBGCP ( device, "EFIPCI %s cannot open PCI protocols: %s\n",
 			efi_handle_name ( device ), strerror ( rc ) );
 		return rc;
 	}
-	efipci->io = pci_io.pci_io;
+	efipci->io = pci_io;
 
 	/* Get PCI bus:dev.fn address */
-	if ( ( efirc = pci_io.pci_io->GetLocation ( pci_io.pci_io, &pci_segment,
-						    &pci_bus, &pci_dev,
-						    &pci_fn ) ) != 0 ) {
+	if ( ( efirc = pci_io->GetLocation ( pci_io, &pci_segment, &pci_bus,
+					     &pci_dev, &pci_fn ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( device, "EFIPCI %s could not get PCI location: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
@@ -781,15 +765,12 @@ int efipci_info ( EFI_HANDLE device, struct efi_pci_device *efipci ) {
 	 * support I/O cycles).  Work around any such platforms by
 	 * enabling bits individually and simply ignoring any errors.
 	 */
-	pci_io.pci_io->Attributes ( pci_io.pci_io,
-				    EfiPciIoAttributeOperationEnable,
-				    EFI_PCI_IO_ATTRIBUTE_IO, NULL );
-	pci_io.pci_io->Attributes ( pci_io.pci_io,
-				    EfiPciIoAttributeOperationEnable,
-				    EFI_PCI_IO_ATTRIBUTE_MEMORY, NULL );
-	pci_io.pci_io->Attributes ( pci_io.pci_io,
-				    EfiPciIoAttributeOperationEnable,
-				    EFI_PCI_IO_ATTRIBUTE_BUS_MASTER, NULL );
+	pci_io->Attributes ( pci_io, EfiPciIoAttributeOperationEnable,
+			     EFI_PCI_IO_ATTRIBUTE_IO, NULL );
+	pci_io->Attributes ( pci_io, EfiPciIoAttributeOperationEnable,
+			     EFI_PCI_IO_ATTRIBUTE_MEMORY, NULL );
+	pci_io->Attributes ( pci_io, EfiPciIoAttributeOperationEnable,
+			     EFI_PCI_IO_ATTRIBUTE_BUS_MASTER, NULL );
 
 	/* Populate PCI device */
 	if ( ( rc = pci_read_config ( &efipci->pci ) ) != 0 ) {
@@ -857,7 +838,6 @@ static int efipci_supported ( EFI_HANDLE device ) {
 static int efipci_start ( struct efi_device *efidev ) {
 	EFI_HANDLE device = efidev->device;
 	struct efi_pci_device *efipci;
-	void *pci_io;
 	int rc;
 
 	/* Allocate PCI device */
@@ -873,7 +853,7 @@ static int efipci_start ( struct efi_device *efidev ) {
 
 	/* Open PCI I/O protocol */
 	if ( ( rc = efi_open_by_driver ( device, &efi_pci_io_protocol_guid,
-					 &pci_io ) ) != 0 ) {
+					 &efipci->io ) ) != 0 ) {
 		DBGC ( device, "EFIPCI %s could not open PCI device: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		DBGC_EFI_OPENERS ( device, device, &efi_pci_io_protocol_guid );
diff --git a/src/interface/efi/efi_service.c b/src/interface/efi/efi_service.c
index de7353652..f10733b24 100644
--- a/src/interface/efi/efi_service.c
+++ b/src/interface/efi/efi_service.c
@@ -45,15 +45,12 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  */
 int efi_service_add ( EFI_HANDLE service, EFI_GUID *binding,
 		      EFI_HANDLE *handle ) {
-	union {
-		EFI_SERVICE_BINDING_PROTOCOL *sb;
-		void *interface;
-	} u;
+	EFI_SERVICE_BINDING_PROTOCOL *sb;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Open service binding protocol */
-	if ( ( rc = efi_open ( service, binding, &u.interface ) ) != 0 ) {
+	if ( ( rc = efi_open ( service, binding, &sb ) ) != 0 ) {
 		DBGC ( service, "EFISVC %s cannot open %s binding: %s\n",
 		       efi_handle_name ( service ), efi_guid_ntoa ( binding ),
 		       strerror ( rc ) );
@@ -61,7 +58,7 @@ int efi_service_add ( EFI_HANDLE service, EFI_GUID *binding,
 	}
 
 	/* Create child handle */
-	if ( ( efirc = u.sb->CreateChild ( u.sb, handle ) ) != 0 ) {
+	if ( ( efirc = sb->CreateChild ( sb, handle ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( service, "EFISVC %s could not create %s child: %s\n",
 		       efi_handle_name ( service ), efi_guid_ntoa ( binding ),
@@ -85,10 +82,7 @@ int efi_service_add ( EFI_HANDLE service, EFI_GUID *binding,
  */
 int efi_service_del ( EFI_HANDLE service, EFI_GUID *binding,
 		      EFI_HANDLE handle ) {
-	union {
-		EFI_SERVICE_BINDING_PROTOCOL *sb;
-		void *interface;
-	} u;
+	EFI_SERVICE_BINDING_PROTOCOL *sb;
 	EFI_STATUS efirc;
 	int rc;
 
@@ -97,7 +91,7 @@ int efi_service_del ( EFI_HANDLE service, EFI_GUID *binding,
 	DBGC ( service, "%s\n", efi_handle_name ( handle ) );
 
 	/* Open service binding protocol */
-	if ( ( rc = efi_open ( service, binding, &u.interface ) ) != 0 ) {
+	if ( ( rc = efi_open ( service, binding, &sb ) ) != 0 ) {
 		DBGC ( service, "EFISVC %s cannot open %s binding: %s\n",
 		       efi_handle_name ( service ), efi_guid_ntoa ( binding ),
 		       strerror ( rc ) );
@@ -105,7 +99,7 @@ int efi_service_del ( EFI_HANDLE service, EFI_GUID *binding,
 	}
 
 	/* Destroy child handle */
-	if ( ( efirc = u.sb->DestroyChild ( u.sb, handle ) ) != 0 ) {
+	if ( ( efirc = sb->DestroyChild ( sb, handle ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( service, "EFISVC %s could not destroy %s child ",
 		       efi_handle_name ( service ), efi_guid_ntoa ( binding ) );
diff --git a/src/interface/efi/efi_shim.c b/src/interface/efi/efi_shim.c
index 02bd0791f..4bb6df79f 100644
--- a/src/interface/efi/efi_shim.c
+++ b/src/interface/efi/efi_shim.c
@@ -272,23 +272,20 @@ static EFIAPI EFI_STATUS efi_shim_get_memory_map ( UINTN *len,
  * @ret rc		Return status code
  */
 static int efi_shim_inhibit_pxe ( EFI_HANDLE handle ) {
-	union {
-		EFI_PXE_BASE_CODE_PROTOCOL *pxe;
-		void *interface;
-	} u;
+	EFI_PXE_BASE_CODE_PROTOCOL *pxe;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Locate PXE base code */
 	if ( ( rc = efi_open ( handle, &efi_pxe_base_code_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &pxe ) ) != 0 ) {
 		DBGC ( &efi_shim, "SHIM could not open PXE base code: %s\n",
 		       strerror ( rc ) );
 		return rc;
 	}
 
 	/* Stop PXE base code */
-	if ( ( efirc = u.pxe->Stop ( u.pxe ) ) != 0 ) {
+	if ( ( efirc = pxe->Stop ( pxe ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( &efi_shim, "SHIM could not stop PXE base code: %s\n",
 		       strerror ( rc ) );
diff --git a/src/interface/efi/efi_utils.c b/src/interface/efi/efi_utils.c
index 4f081b67f..51da06172 100644
--- a/src/interface/efi/efi_utils.c
+++ b/src/interface/efi/efi_utils.c
@@ -45,10 +45,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 int efi_locate_device ( EFI_HANDLE device, EFI_GUID *protocol,
 			EFI_HANDLE *parent, unsigned int skip ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
-	union {
-		EFI_DEVICE_PATH_PROTOCOL *path;
-		void *interface;
-	} u;
+	EFI_DEVICE_PATH_PROTOCOL *devpath;
 	EFI_DEVICE_PATH_PROTOCOL *path;
 	EFI_DEVICE_PATH_PROTOCOL *end;
 	size_t len;
@@ -57,20 +54,20 @@ int efi_locate_device ( EFI_HANDLE device, EFI_GUID *protocol,
 
 	/* Get device path */
 	if ( ( rc = efi_open ( device, &efi_device_path_protocol_guid,
-			       &u.interface ) ) != 0 ) {
+			       &devpath ) ) != 0 ) {
 		DBGC ( device, "EFIDEV %s cannot open device path: %s\n",
 		       efi_handle_name ( device ), strerror ( rc ) );
 		goto err_open_device_path;
 	}
 
 	/* Create modifiable copy of device path */
-	len = ( efi_path_len ( u.path ) + sizeof ( EFI_DEVICE_PATH_PROTOCOL ));
+	len = ( efi_path_len ( devpath ) + sizeof ( *end ) );
 	path = malloc ( len );
 	if ( ! path ) {
 		rc = -ENOMEM;
 		goto err_alloc_path;
 	}
-	memcpy ( path, u.path, len );
+	memcpy ( path, devpath, len );
 
 	/* Locate parent device(s) */
 	while ( 1 ) {
@@ -111,7 +108,7 @@ int efi_locate_device ( EFI_HANDLE device, EFI_GUID *protocol,
  * @ret rc		Return status code
  */
 int efi_child_add ( EFI_HANDLE parent, EFI_HANDLE child ) {
-	void *devpath;
+	EFI_DEVICE_PATH_PROTOCOL *devpath;
 	int rc;
 
 	/* Re-open the device path protocol */
diff --git a/src/interface/efi/efi_veto.c b/src/interface/efi/efi_veto.c
index 637eee016..3f9c9940e 100644
--- a/src/interface/efi/efi_veto.c
+++ b/src/interface/efi/efi_veto.c
@@ -153,16 +153,13 @@ static int efi_veto_disconnect ( struct efi_veto *veto ) {
 static int efi_veto_uninstall ( struct efi_veto *veto ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	EFI_HANDLE driver = veto->driver;
-	union {
-		EFI_DRIVER_BINDING_PROTOCOL *binding;
-		void *interface;
-	} binding;
+	EFI_DRIVER_BINDING_PROTOCOL *binding;
 	EFI_STATUS efirc;
 	int rc;
 
 	/* Open driver binding protocol */
 	if ( ( rc = efi_open ( driver, &efi_driver_binding_protocol_guid,
-			       &binding.interface ) ) != 0 ) {
+			       &binding ) ) != 0 ) {
 		DBGC ( driver, "EFIVETO %s could not open driver binding "
 		       "protocol: %s\n", efi_handle_name ( driver ),
 		       strerror ( rc ) );
@@ -172,7 +169,7 @@ static int efi_veto_uninstall ( struct efi_veto *veto ) {
 	/* Uninstall driver binding protocol */
 	if ( ( efirc = bs->UninstallMultipleProtocolInterfaces (
 			driver, &efi_driver_binding_protocol_guid,
-			binding.binding, NULL ) ) != 0 ) {
+			binding, NULL ) ) != 0 ) {
 		rc = -EEFI ( efirc );
 		DBGC ( driver, "EFIVETO %s could not uninstall driver "
 		       "binding protocol: %s\n",
@@ -534,22 +531,10 @@ static struct efi_veto_candidate efi_vetoes[] = {
  */
 static int efi_veto_find ( EFI_HANDLE driver, const char *manufacturer,
 			   struct efi_veto *veto ) {
-	union {
-		EFI_DRIVER_BINDING_PROTOCOL *binding;
-		void *interface;
-	} binding;
-	union {
-		EFI_LOADED_IMAGE_PROTOCOL *loaded;
-		void *interface;
-	} loaded;
-	union {
-		EFI_COMPONENT_NAME2_PROTOCOL *wtf2;
-		void *interface;
-	} wtf2;
-	union {
-		EFI_COMPONENT_NAME_PROTOCOL *wtf;
-		void *interface;
-	} wtf;
+	EFI_DRIVER_BINDING_PROTOCOL *binding;
+	EFI_LOADED_IMAGE_PROTOCOL *loaded;
+	EFI_COMPONENT_NAME2_PROTOCOL *wtf2;
+	EFI_COMPONENT_NAME_PROTOCOL *wtf;
 	CHAR16 *name;
 	unsigned int i;
 	EFI_HANDLE image;
@@ -561,17 +546,17 @@ static int efi_veto_find ( EFI_HANDLE driver, const char *manufacturer,
 
 	/* Open driver binding protocol */
 	if ( ( rc = efi_open ( driver, &efi_driver_binding_protocol_guid,
-			       &binding.interface ) ) != 0 ) {
+			       &binding ) ) != 0 ) {
 		DBGC ( driver, "EFIVETO %s could not open driver binding "
 		       "protocol: %s\n", efi_handle_name ( driver ),
 		       strerror ( rc ) );
 		return rc;
 	}
-	image = binding.binding->ImageHandle;
+	image = binding->ImageHandle;
 
 	/* Open loaded image protocol */
 	if ( ( rc = efi_open ( image, &efi_loaded_image_protocol_guid,
-			       &loaded.interface ) ) != 0 ) {
+			       &loaded ) ) != 0 ) {
 		DBGC ( driver, "EFIVETO %s could not open",
 		       efi_handle_name ( driver ) );
 		DBGC ( driver, " %s loaded image protocol: %s\n",
@@ -581,23 +566,21 @@ static int efi_veto_find ( EFI_HANDLE driver, const char *manufacturer,
 
 	/* Open component name protocol, if present */
 	if ( ( rc = efi_open ( image, &efi_component_name2_protocol_guid,
-			       &wtf2.interface ) ) != 0 ) {
+			       &wtf2 ) ) != 0 ) {
 		/* Ignore failure; is not required to be present */
 	}
 
 	/* Open obsolete component name protocol, if present */
 	if ( ( rc = efi_open ( image, &efi_component_name_protocol_guid,
-			       &wtf.interface ) ) != 0 ) {
+			       &wtf ) ) != 0 ) {
 		/* Ignore failure; is not required to be present */
 	}
 
 	/* Get driver name, if available */
-	if ( ( wtf2.wtf2 &&
-	       ( ( efirc = wtf2.wtf2->GetDriverName ( wtf2.wtf2, "en",
-						      &name ) == 0 ) ) ) ||
-	     ( wtf.wtf &&
-	       ( ( efirc = wtf.wtf->GetDriverName ( wtf.wtf, "eng",
-						    &name ) == 0 ) ) ) ) {
+	if ( ( wtf2 && ( ( efirc = wtf2->GetDriverName ( wtf2, "en",
+							 &name ) == 0 ) ) ) ||
+	     ( wtf && ( ( efirc = wtf->GetDriverName ( wtf, "eng",
+						       &name ) == 0 ) ) ) ) {
 		/* Driver has a name */
 	} else {
 		/* Ignore failure; name is not required to be present */
@@ -606,19 +589,19 @@ static int efi_veto_find ( EFI_HANDLE driver, const char *manufacturer,
 
 	/* Check vetoes */
 	DBGC2 ( &efi_vetoes, "EFIVETO checking %s [%p,%p)\n",
-		efi_handle_name ( driver ), loaded.loaded->ImageBase,
-		( loaded.loaded->ImageBase + loaded.loaded->ImageSize ) );
+		efi_handle_name ( driver ), loaded->ImageBase,
+		( loaded->ImageBase + loaded->ImageSize ) );
 	for ( i = 0 ; i < ( sizeof ( efi_vetoes ) /
 			    sizeof ( efi_vetoes[0] ) ) ; i++ ) {
-		if ( efi_vetoes[i].veto ( binding.binding, loaded.loaded,
-					  manufacturer, name ) ) {
+		if ( efi_vetoes[i].veto ( binding, loaded, manufacturer,
+					  name ) ) {
 			DBGC ( driver, "EFIVETO %s is vetoed (%s)\n",
 			       efi_handle_name ( driver ),
 			       efi_vetoes[i].name );
 			veto->driver = driver;
-			veto->binding = binding.binding;
+			veto->binding = binding;
 			veto->image = image;
-			veto->loaded = loaded.loaded;
+			veto->loaded = loaded;
 			break;
 		}
 	}
diff --git a/src/interface/efi/efi_wrap.c b/src/interface/efi/efi_wrap.c
index 1cc37f3e3..a806a7c60 100644
--- a/src/interface/efi/efi_wrap.c
+++ b/src/interface/efi/efi_wrap.c
@@ -248,15 +248,12 @@ static int efi_prescroll ( unsigned int lines ) {
  * @v handle		Image handle
  */
 static void efi_dump_image ( EFI_HANDLE handle ) {
-	union {
-		EFI_LOADED_IMAGE_PROTOCOL *image;
-		void *intf;
-	} loaded;
+	EFI_LOADED_IMAGE_PROTOCOL *loaded;
 	int rc;
 
 	/* Open loaded image protocol */
 	if ( ( rc = efi_open ( handle, &efi_loaded_image_protocol_guid,
-			       &loaded.intf ) ) != 0 ) {
+			       &loaded ) ) != 0 ) {
 		DBGC ( colour, "WRAP %s could not get loaded image protocol: "
 		       "%s\n", efi_handle_name ( handle ), strerror ( rc ) );
 		return;
@@ -264,14 +261,14 @@ static void efi_dump_image ( EFI_HANDLE handle ) {
 
 	/* Dump image information */
 	DBGC ( colour, "WRAP %s at base %p has protocols:\n",
-	       efi_handle_name ( handle ), loaded.image->ImageBase );
+	       efi_handle_name ( handle ), loaded->ImageBase );
 	DBGC_EFI_PROTOCOLS ( colour, handle );
 	DBGC ( colour, "WRAP %s parent", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->ParentHandle ));
+	DBGC ( colour, " %s\n", efi_handle_name ( loaded->ParentHandle ) );
 	DBGC ( colour, "WRAP %s device", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_handle_name ( loaded.image->DeviceHandle ));
+	DBGC ( colour, " %s\n", efi_handle_name ( loaded->DeviceHandle ) );
 	DBGC ( colour, "WRAP %s file", efi_handle_name ( handle ) );
-	DBGC ( colour, " %s\n", efi_devpath_text ( loaded.image->FilePath ) );
+	DBGC ( colour, " %s\n", efi_devpath_text ( loaded->FilePath ) );
 }
 
 /**