Index: sys/ufs/ffs/ffs_subr.c
===================================================================
RCS file: /cvsroot/src/sys/ufs/ffs/ffs_subr.c,v
retrieving revision 1.50
diff -u -r1.50 ffs_subr.c
--- sys/ufs/ffs/ffs_subr.c	4 Jul 2018 02:02:15 -0000	1.50
+++ sys/ufs/ffs/ffs_subr.c	27 May 2019 16:58:29 -0000
@@ -313,7 +313,7 @@
 		end = ufs_rw32(cgp->cg_nclusterblks, needswap);
 	mapp = &freemapp[start / NBBY];
 	map = *mapp++;
-	bit = 1U << (start % NBBY);
+	bit = 1U << ((unsigned int)start % NBBY);
 	for (i = start; i < end; i++) {
 		if ((map & bit) == 0)
 			break;
@@ -334,7 +334,7 @@
 		end = -1;
 	mapp = &freemapp[start / NBBY];
 	map = *mapp--;
-	bit = 1U << (start % NBBY);
+	bit = 1U << ((unsigned int)start % NBBY);
 	for (i = start; i > end; i--) {
 		if ((map & bit) == 0)
 			break;