diff --git a/SDL2pp/Window.cc b/SDL2pp/Window.cc
index ab9b621..534ffa8 100644
--- a/SDL2pp/Window.cc
+++ b/SDL2pp/Window.cc
@@ -144,7 +144,7 @@ Window& Window::SetFullscreen(Uint32 flags) {
 
 Window& Window::ToggleFullscreen() {
 	Uint32 const fullscreenFlag = SDL_WINDOW_FULLSCREEN | SDL_WINDOW_FULLSCREEN_DESKTOP;
-	bool const isFullscreen = SDL_GetWindowFlags(mpWindow) & fullscreenFlag;
+	bool const isFullscreen = SDL_GetWindowFlags(window_) & fullscreenFlag;
 	if (SDL_SetWindowFullscreen(window_, isFullscreen ? SDL_FALSE : SDL_WINDOW_FULLSCREEN_DESKTOP) != 0)
 		throw Exception("SDL_SetWindowFullscreen");
 	return *this;