diff --git a/obs/double-slider.hpp b/obs/double-slider.hpp
index d83d15e02..fff6b5bb1 100644
--- a/obs/double-slider.hpp
+++ b/obs/double-slider.hpp
@@ -1,3 +1,5 @@
+#pragma once
+
 #include <QSlider>
 
 class DoubleSlider : public QSlider {