diff --git a/sys/netinet/tcp_stacks/fastpath.c b/sys/netinet/tcp_stacks/fastpath.c
index d4a9ee0566e..5eddccfbdcc 100644
--- a/sys/netinet/tcp_stacks/fastpath.c
+++ b/sys/netinet/tcp_stacks/fastpath.c
@@ -124,7 +124,7 @@ __FBSDID("$FreeBSD$");
 
 #include <security/mac/mac_framework.h>
 
-const int tcprexmtthresh;
+extern const int tcprexmtthresh;
 
 VNET_DECLARE(int, tcp_autorcvbuf_inc);
 #define	V_tcp_autorcvbuf_inc	VNET(tcp_autorcvbuf_inc)