diff --git a/src/util/gc_stat.h b/src/util/gc_stat.h
index 7c7b420..db45753 100644
--- a/src/util/gc_stat.h
+++ b/src/util/gc_stat.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "nasal.h"
 #include "nasal_type.h"