diff --git a/sys/libkern/ffs.c b/sys/libkern/ffs.c
index f945f5d61f6..6c4d97e634d 100644
--- a/sys/libkern/ffs.c
+++ b/sys/libkern/ffs.c
@@ -47,6 +47,6 @@ ffs(int mask)
 	if (mask == 0)
 		return (0);
 	for (bit = 1; !(mask & 1); bit++)
-		mask >>= 1;
+		(unsigned int)mask >>= 1;
 	return (bit);
 }
diff --git a/sys/libkern/ffsl.c b/sys/libkern/ffsl.c
index 11b29b40a53..74b53f89f3b 100644
--- a/sys/libkern/ffsl.c
+++ b/sys/libkern/ffsl.c
@@ -47,6 +47,6 @@ ffsl(long mask)
 	if (mask == 0)
 		return (0);
 	for (bit = 1; !(mask & 1); bit++)
-		mask >>= 1;
+		(unsigned long)mask >>= 1;
 	return (bit);
 }
diff --git a/sys/libkern/fls.c b/sys/libkern/fls.c
index 5de4771ecaf..ca41b6d09a2 100644
--- a/sys/libkern/fls.c
+++ b/sys/libkern/fls.c
@@ -47,6 +47,6 @@ fls(int mask)
 	if (mask == 0)
 		return (0);
 	for (bit = 1; mask != 1; bit++)
-		mask >>= 1;
+		(unsigned int)mask >>= 1;
 	return (bit);
 }
diff --git a/sys/libkern/flsl.c b/sys/libkern/flsl.c
index 24742f286a4..b46813f4f94 100644
--- a/sys/libkern/flsl.c
+++ b/sys/libkern/flsl.c
@@ -47,6 +47,6 @@ flsl(long mask)
 	if (mask == 0)
 		return (0);
 	for (bit = 1; mask != 1; bit++)
-		mask >>= 1;
+		(unsigned long)mask >>= 1;
 	return (bit);
 }