diff --git a/sys/net/if_strings.h b/sys/net/if_strings.h
--- a/sys/net/if_strings.h
+++ b/sys/net/if_strings.h
@@ -26,6 +26,8 @@
 #ifndef _NET_IF_STRINGS_H_
 #define _NET_IF_STRINGS_H_
 
+#include <sys/cdefs.h>
+
 #define	IFCAP_RXCSUM_NAME		"RXCSUM"
 #define	IFCAP_TXCSUM_NAME		"TXCSUM"
 #define	IFCAP_NETCONS_NAME		"NETCONS"
@@ -66,7 +68,7 @@
 #define	IFCAP2_RXTLS6_NAME	IFCAP_RXTLS6_NAME
 #define	IFCAP2_IPSEC_OFFLOAD_NAME IFCAP_IPSEC_OFFLOAD_NAME
 
-static const char *ifcap_bit_names[] = {
+static const char *ifcap_bit_names[] __unused = {
 	IFCAP_RXCSUM_NAME,
 	IFCAP_TXCSUM_NAME,
 	IFCAP_NETCONS_NAME,
diff --git a/sys/net/sff8472.h b/sys/net/sff8472.h
--- a/sys/net/sff8472.h
+++ b/sys/net/sff8472.h
@@ -26,6 +26,11 @@
  * SUCH DAMAGE.
  */
 
+#ifndef _NET_SFF8472_H_
+#define _NET_SFF8472_H_
+
+#include <sys/cdefs.h>
+
 /*
  * The following set of constants are from Document SFF-8472
  * "Diagnostic Monitoring Interface for Optical Transceivers" revision
@@ -415,7 +420,7 @@
 	SFF_8024_ID_LAST	= SFF_8024_ID_QSFP_CMIS
 };
 
-static const char *sff_8024_id[SFF_8024_ID_LAST + 1] = {
+static const char *sff_8024_id[SFF_8024_ID_LAST + 1] __unused = {
 	"Unknown",
 	"GBIC",
 	"SFF",
@@ -524,3 +529,5 @@
  */
 
 #define SFF_8472_POWER_FACTOR 10000.0
+
+#endif