diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c
index 60d5df112..c5deb08f6 100644
--- a/src/drivers/bus/pci.c
+++ b/src/drivers/bus/pci.c
@@ -352,8 +352,7 @@ static int pcibus_probe ( struct root_device *rootdev ) {
 	uint32_t busdevfn = 0;
 	int rc;
 
-	for ( busdevfn = 0 ; 1 ; busdevfn++ ) {
-
+	do {
 		/* Allocate struct pci_device */
 		if ( ! pci )
 			pci = malloc ( sizeof ( *pci ) );
@@ -386,7 +385,8 @@ static int pcibus_probe ( struct root_device *rootdev ) {
 			/* Not registered; re-use struct pci_device */
 			list_del ( &pci->dev.siblings );
 		}
-	}
+
+	} while ( ++busdevfn );
 
 	free ( pci );
 	return 0;
diff --git a/src/hci/commands/pci_cmd.c b/src/hci/commands/pci_cmd.c
index 515798baf..5bae66fbe 100644
--- a/src/hci/commands/pci_cmd.c
+++ b/src/hci/commands/pci_cmd.c
@@ -22,6 +22,7 @@
  */
 
 #include <stdio.h>
+#include <errno.h>
 #include <getopt.h>
 #include <ipxe/pci.h>
 #include <ipxe/command.h>
@@ -79,6 +80,10 @@ static int pciscan_exec ( int argc, char **argv ) {
 	} else {
 		/* Setting is defined: start searching from next location */
 		busdevfn = ( prev + 1 );
+		if ( ! busdevfn ) {
+			rc = -ENOENT;
+			goto err_end;
+		}
 	}
 
 	/* Find next existent PCI device */
@@ -101,6 +106,7 @@ static int pciscan_exec ( int argc, char **argv ) {
 	}
 
  err_store:
+ err_end:
  err_find_next:
  err_parse_setting:
  err_parse_options:
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 359e4d2ce..9b955e574 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -397,6 +397,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_linux_sysfs	      ( ERRFILE_OTHER | 0x00560000 )
 #define ERRFILE_linux_acpi	      ( ERRFILE_OTHER | 0x00570000 )
 #define ERRFILE_dynkeymap	      ( ERRFILE_OTHER | 0x00580000 )
+#define ERRFILE_pci_cmd		      ( ERRFILE_OTHER | 0x00590000 )
 
 /** @} */