diff --git a/libntfs/volume.c b/libntfs/volume.c
index ca6dcd7e..1f27b516 100644
--- a/libntfs/volume.c
+++ b/libntfs/volume.c
@@ -787,8 +787,8 @@ ntfs_volume *ntfs_device_mount(struct ntfs_device *dev, unsigned long rwflag)
 		if (l == -1)
 			ntfs_log_perror("Failed to read $MFT");
 		else {
-			ntfs_log_debug("Length of data not equal expected "
-					"length.\n");
+			ntfs_log_debug("Failed to read $MFT, unexpected length "
+				       "(%d != %lld).\n", vol->mftmirr_size, l);
 			errno = EIO;
 		}
 		goto error_exit;
@@ -799,8 +799,9 @@ ntfs_volume *ntfs_device_mount(struct ntfs_device *dev, unsigned long rwflag)
 		if (l == -1)
 			ntfs_log_perror("Failed to read $MFTMirr");
 		else {
-			ntfs_log_debug("Length of data not equal expected "
-					"length.\n");
+			ntfs_log_debug("Failed to read $MFTMirr, unexpected "
+				       "length (%d != %lld).\n", 
+				       vol->mftmirr_size, l);
 			errno = EIO;
 		}
 		goto error_exit;