diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 760172a65aff..d7d06dc89eb7 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -288,6 +288,8 @@ xfs_rtfind_forw(
 	xfs_rtword_t	wdiff;		/* difference from wanted value */
 	int		word;		/* word number in the buffer */
 
+	ASSERT(start <= limit);
+
 	/*
 	 * Compute and read in starting bitmap block for starting block.
 	 */