diff --git a/libultraship/libultraship/Lib/Fast3D/gfx_sdl2.cpp b/libultraship/libultraship/Lib/Fast3D/gfx_sdl2.cpp
index 061e3a8ee..42ffd69eb 100644
--- a/libultraship/libultraship/Lib/Fast3D/gfx_sdl2.cpp
+++ b/libultraship/libultraship/Lib/Fast3D/gfx_sdl2.cpp
@@ -34,8 +34,8 @@ static SDL_Window *wnd;
 static SDL_GLContext ctx;
 static int inverted_scancode_table[512];
 static int vsync_enabled = 0;
-static unsigned int window_width = DESIRED_SCREEN_WIDTH;
-static unsigned int window_height = DESIRED_SCREEN_HEIGHT;
+static int window_width = DESIRED_SCREEN_WIDTH;
+static int window_height = DESIRED_SCREEN_HEIGHT;
 static bool fullscreen_state;
 static void (*on_fullscreen_changed_callback)(bool is_now_fullscreen);
 static bool (*on_key_down_callback)(int scancode);
@@ -145,7 +145,8 @@ static void gfx_sdl_init(const char *game_name, bool start_in_fullscreen) {
     int len = sprintf(title, "%s (%s)", game_name, GFX_API_NAME);
 
     wnd = SDL_CreateWindow(title, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
-            window_width, window_height, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE);
+            window_width, window_height, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    SDL_GL_GetDrawableSize(wnd, &window_width, &window_height);
 
     if (start_in_fullscreen) {
         set_fullscreen(true, false);
@@ -244,8 +245,7 @@ static void gfx_sdl_handle_events(void) {
 #endif
             case SDL_WINDOWEVENT:
                 if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
-                    window_width = event.window.data1;
-                    window_height = event.window.data2;
+                    SDL_GL_GetDrawableSize(wnd, &window_width, &window_height);
                 }
                 break;
             case SDL_QUIT: