diff --git a/binding-mri/journal-binding.h b/binding-mri/journal-binding.h
index 3d14e02..36f315c 100644
--- a/binding-mri/journal-binding.h
+++ b/binding-mri/journal-binding.h
@@ -1,3 +1,5 @@
+#pragma once
+
 #include "binding-util.h"
 #include "binding-types.h"
 #include "pipe.h"