diff --git a/Source/Core/UICommon/CommandLineParse.h b/Source/Core/UICommon/CommandLineParse.h
index d1d52c19b0..86bc6c99b2 100644
--- a/Source/Core/UICommon/CommandLineParse.h
+++ b/Source/Core/UICommon/CommandLineParse.h
@@ -2,6 +2,8 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
+#pragma once
+
 #include <memory>
 #include <string>
 #include <vector>