diff --git a/usr.sbin/fstyp/Makefile b/usr.sbin/fstyp/Makefile
--- a/usr.sbin/fstyp/Makefile
+++ b/usr.sbin/fstyp/Makefile
@@ -12,8 +12,6 @@
 
 MAN=	fstyp.8
 
-WARNS?=	2
-
 .if ${MK_ICONV} == "yes"
 CFLAGS+=	-DWITH_ICONV
 .endif
diff --git a/usr.sbin/fstyp/apfs.c b/usr.sbin/fstyp/apfs.c
--- a/usr.sbin/fstyp/apfs.c
+++ b/usr.sbin/fstyp/apfs.c
@@ -100,6 +100,8 @@
 	retval = 0;
 
 	/* No label support yet. */
+	(void)size;
+	(void)label;
 
 fail:
 	free(csb);
diff --git a/usr.sbin/fstyp/fstyp.c b/usr.sbin/fstyp/fstyp.c
--- a/usr.sbin/fstyp/fstyp.c
+++ b/usr.sbin/fstyp/fstyp.c
@@ -61,7 +61,7 @@
 	const char	*name;
 	fstyp_function	function;
 	bool		unmountable;
-	char		*precache_encoding;
+	const char	*precache_encoding;
 } fstypes[] = {
 	{ "apfs", &fstyp_apfs, true, NULL },
 	{ "befs", &fstyp_befs, false, NULL },
@@ -206,7 +206,7 @@
 #ifdef WITH_ICONV
 	/* Cache iconv conversion data before entering capability mode. */
 	if (show_label) {
-		for (i = 0; i < nitems(fstypes); i++) {
+		for (i = 0; i < (int)nitems(fstypes); i++) {
 			iconv_t cd;
 
 			if (fstypes[i].precache_encoding == NULL)
diff --git a/usr.sbin/fstyp/hammer.c b/usr.sbin/fstyp/hammer.c
--- a/usr.sbin/fstyp/hammer.c
+++ b/usr.sbin/fstyp/hammer.c
@@ -43,6 +43,9 @@
 
 #include "fstyp.h"
 
+extern int fsvtyp_hammer(const char *blkdevs, char *label, size_t size);
+extern int fsvtyp_hammer_partial(const char *blkdevs, char *label, size_t size);
+
 static hammer_volume_ondisk_t
 read_ondisk(FILE *fp)
 {
diff --git a/usr.sbin/fstyp/hfsplus.c b/usr.sbin/fstyp/hfsplus.c
--- a/usr.sbin/fstyp/hfsplus.c
+++ b/usr.sbin/fstyp/hfsplus.c
@@ -118,6 +118,8 @@
 	retval = 0;
 
 	/* No label support yet. */
+	(void)size;
+	(void)label;
 
 fail:
 	free(hdr);