diff --git a/sys/ddb/db_sym.c b/sys/ddb/db_sym.c
index 3fdf80a76ae6..8883d84fcace 100644
--- a/sys/ddb/db_sym.c
+++ b/sys/ddb/db_sym.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_kstack_pages.h"
 
 #include <sys/param.h>
+#include <sys/systm.h>
 #include <sys/pcpu.h>
 #include <sys/smp.h>
 #include <sys/sysent.h>