diff --git a/bin/df/df.c b/bin/df/df.c
index 27f0fd7255f7..3cec5ddcbd74 100644
--- a/bin/df/df.c
+++ b/bin/df/df.c
@@ -527,8 +527,8 @@ char *makenetvfslist()
 
 	mib[0] = CTL_VFS; mib[1] = VFS_GENERIC; mib[2] = VFS_MAXTYPENUM;
 	miblen=sizeof(maxvfsconf);
-	if (sysctl(mib, (u_int) sizeof (mib) / sizeof(mib[0]), &maxvfsconf,
-	    &miblen, NULL, 0)) {
+	if (sysctl(mib, (unsigned int)(sizeof(mib) / sizeof(mib[0])),
+	    &maxvfsconf, &miblen, NULL, 0)) {
 		warnx("sysctl failed");
 		return (NULL);
 	}