diff --git a/source/src/main.cpp b/source/src/main.cpp
index 8e3fadd5..d785a865 100644
--- a/source/src/main.cpp
+++ b/source/src/main.cpp
@@ -37,8 +37,8 @@ void fatal(char *s, char *o)    // failure exit
 	exit(EXIT_FAILURE);
 }
 
-int scr_w = 640;
-int scr_h = 480;
+int scr_w = 1024;
+int scr_h = 768;
 int VIRTW;
 
 void screenshot(char *imagepath)
@@ -228,6 +228,16 @@ int main(int argc, char **argv)
     #if defined(WIN32) || defined(__APPLE__)
     resize = 0;
     #endif
+    SDL_Rect **modes = SDL_ListModes(NULL, SDL_OPENGL|resize|fs);
+    if(modes && modes!=(SDL_Rect **)-1)
+    {
+        bool hasmode = false;
+        for(int i = 0; modes[i]; i++)
+        {
+            if(scr_w <= modes[i]->w && scr_h <= modes[i]->h) { hasmode = true; break; }
+        }
+        if(!hasmode) { scr_w = modes[0]->w; scr_h = modes[0]->h; }
+    }
     screen = SDL_SetVideoMode(scr_w, scr_h, bpp, SDL_OPENGL|resize|fs);
     if(screen==NULL) fatal("Unable to create OpenGL screen");
     fullscreen = fs!=0;