diff --git a/src/menu.cpp b/src/menu.cpp
index 7a0d2d9b9..88f5a3986 100644
--- a/src/menu.cpp
+++ b/src/menu.cpp
@@ -649,7 +649,6 @@ short GraphicsDlg(stCloneKeenPlus *pCKP)
 	unsigned short zoom = 1;
 	unsigned short filter = 0;
 	unsigned short frameskip = 0;
-	bool opengl = false;
 	unsigned char gl_filter = 0;
 	bool fsmode;
 	char buf[256];
@@ -689,7 +688,7 @@ short GraphicsDlg(stCloneKeenPlus *pCKP)
 		fsmode = false;
 	}
 
-	opengl = g_pVideoDriver->isOpenGL();
+	bool opengl = g_pVideoDriver->isOpenGL();
 	if(!opengl)
 	{
 		zoom = g_pVideoDriver->getZoomValue();
@@ -844,7 +843,7 @@ short GraphicsDlg(stCloneKeenPlus *pCKP)
 			}
 			else if(selection == 5)
 			{
-				opengl = opengl ? false : true; // switch the mode!!
+				opengl = !opengl; // switch the mode!!
 
 				if(opengl)
 					DisplayMenu->setOptionText(5,"OpenGL Acceleration");
diff --git a/src/sdl/COpenGL.h b/src/sdl/COpenGL.h
index 4b68035cf..5d9ccea88 100644
--- a/src/sdl/COpenGL.h
+++ b/src/sdl/COpenGL.h
@@ -9,6 +9,9 @@
  *
  */
 
+#ifndef __CG_COPENGL_H__
+#define __CG_COPENGL_H__
+
 #include <SDL.h>
 #include <SDL_opengl.h>
 #include "../scale2x/scalebit.h"
@@ -32,3 +35,4 @@ private:
 	unsigned int	m_texparam;
 };
 
+#endif