diff --git a/src/glstate.cpp b/src/glstate.cpp
index ff88de7..610ce50 100644
--- a/src/glstate.cpp
+++ b/src/glstate.cpp
@@ -120,7 +120,7 @@ GLState::GLState(const Config &conf)
 	blendMode.init(BlendNormal);
 	blend.init(true);
 	scissorTest.init(false);
-	scissorBox.init(IntRect(0, 0, 640, 480));
+	scissorBox.init(IntRect(0, 0, conf.defScreenW, conf.defScreenH));
 	program.init(0);
 
 	if (conf.maxTextureSize > 0)