diff --git a/misc/e2image.c b/misc/e2image.c
index 99a2ed9..d52accf 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -874,8 +874,8 @@
 	return ret;
 }
 
-static int initialize_qcow2_image(int fd, ext2_filsys fs,
-			    struct ext2_qcow2_image *image)
+static errcode_t initialize_qcow2_image(int fd, ext2_filsys fs,
+					struct ext2_qcow2_image *image)
 {
 	struct ext2_qcow2_hdr *header;
 	blk64_t total_size, offset;
@@ -883,6 +883,9 @@
 	int cluster_bits = get_bits_from_size(fs->blocksize);
 	struct ext2_super_block *sb = fs->super;
 
+	if (fs->blocksize < 1024)
+		return EINVAL;	/* Can never happen, but just in case... */
+
 	/* Allocate header */
 	ret = ext2fs_get_memzero(sizeof(struct ext2_qcow2_hdr), &header);
 	if (ret)