diff --git a/src/frame.h b/src/frame.h
index 54f75f666d0..01ba8f8f5cf 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -245,7 +245,7 @@ struct frame
     struct x_output *x;
     struct w32_output *w32;
     struct mac_output *mac;
-    int nothing;
+    EMACS_INT nothing;
   }
   output_data;