diff --git a/libs/gfx/source/renderer/deferred.cpp b/libs/gfx/source/renderer/deferred.cpp
index 5183568b..f5a17306 100644
--- a/libs/gfx/source/renderer/deferred.cpp
+++ b/libs/gfx/source/renderer/deferred.cpp
@@ -751,7 +751,10 @@ void main()
 }
 )";
 
-	char const occlusion_pass_fs[] = R"( void main(){} )";
+	char const occlusion_pass_fs[] =
+R"(#version 330
+void main(){}
+)";
 
 	static std::size_t bbox_to_screen_fan(geom::matrix<float, 4, 4> const & camera_transform, geom::box<float, 3> const & b, geom::point<float, 2> * result)
 	{