diff --git a/desktop_version/src/Editor.cpp b/desktop_version/src/Editor.cpp
index 322510bf..497793ce 100644
--- a/desktop_version/src/Editor.cpp
+++ b/desktop_version/src/Editor.cpp
@@ -3175,8 +3175,8 @@ void editorinput(void)
     ed.old_tilex = ed.tilex;
     ed.old_tiley = ed.tiley;
 
-    ed.tilex = key.mousex / 8;
-    ed.tiley = key.mousey / 8;
+    ed.tilex = SDL_clamp(key.mousex, 0, SCREEN_WIDTH_PIXELS - 1) / 8;
+    ed.tiley = SDL_clamp(key.mousey, 0, SCREEN_HEIGHT_PIXELS - 1) / 8;
 
     bool up_pressed = key.isDown(SDLK_UP) || key.isDown(SDL_CONTROLLER_BUTTON_DPAD_UP);
     bool down_pressed = key.isDown(SDLK_DOWN) || key.isDown(SDL_CONTROLLER_BUTTON_DPAD_DOWN);