diff --git a/src/osd/modules/render/sdlglcontext.h b/src/osd/modules/render/sdlglcontext.h
index 0f24cdc36ea..d2055060bd6 100644
--- a/src/osd/modules/render/sdlglcontext.h
+++ b/src/osd/modules/render/sdlglcontext.h
@@ -41,7 +41,7 @@ public:
 			SDL_GL_DeleteContext(m_context);
 	}
 
-	virtual explicit operator bool() const
+	virtual explicit operator bool() const override
 	{
 		return bool(m_context);
 	}