diff --git a/src/platform/qt/GameController.cpp b/src/platform/qt/GameController.cpp
index 7588db1a5..30d93dd6c 100644
--- a/src/platform/qt/GameController.cpp
+++ b/src/platform/qt/GameController.cpp
@@ -339,7 +339,7 @@ void GameController::openGame(bool biosOnly) {
 	}
 
 	m_inputController->recalibrateAxes();
-	memset(m_drawContext, 0xF8, 1024 * VIDEO_HORIZONTAL_PIXELS);
+	memset(m_drawContext, 0xF8, VIDEO_VERTICAL_PIXELS * VIDEO_HORIZONTAL_PIXELS * 4);
 
 	if (!GBAThreadStart(&m_threadContext)) {
 		m_gameOpen = false;