diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 9feeefe53948..4de97c4e8ebd 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -315,6 +315,8 @@ xfs_rtfind_forw(
 	xfs_rtword_t		incore;
 	unsigned int		word;	/* word number in the buffer */
 
+	ASSERT(start <= limit);
+
 	/*
 	 * Compute and read in starting bitmap block for starting block.
 	 */