diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
index b0342b4e316..7ccfff66b20 100644
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -40,7 +40,6 @@
 #endif
 #include <sys/lock.h>
 #include <sys/malloc.h>
-#include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/mbuf.h>
 #include <sys/proc.h>		/* for proc0 declaration */