diff --git a/sys/netncp/ncp_ncp.c b/sys/netncp/ncp_ncp.c
index 7905ed0bbecc..b7799cce8622 100644
--- a/sys/netncp/ncp_ncp.c
+++ b/sys/netncp/ncp_ncp.c
@@ -39,6 +39,7 @@
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/signalvar.h>
+#include <sys/sysctl.h>
 #include <sys/mbuf.h>
 #include <sys/uio.h>