diff --git i/src/w32term.c w/src/w32term.c
index d6b78fd..9627019 100644
--- i/src/w32term.c
+++ w/src/w32term.c
@@ -5110,12 +5110,18 @@ w32_read_socket (struct terminal *terminal,
 		     simple hack to check that based on the fact that
 		     only a maximized fullscreen frame should have both
 		     top/left outside the screen.  */
+                    {
+                      AUTO_STRING (format, "SIZE_MAXIMIZED, fullscreen = %s");
+                      CALLN (Fmessage, format, SYMBOL_NAME (fullscreen));
+                    }
 		  if (EQ (fullscreen, Qfullwidth) || EQ (fullscreen, Qfullheight)
 		      || NILP (fullscreen))
 		      {
 			int x, y;
 
 			x_real_positions (f, &x, &y);
+                        AUTO_STRING (format, "SIZE_MAXIMIZED, x = %d, y = %d");
+                        CALLN (Fmessage, format, make_number (x), make_number (y));
 			if (x < 0 && y < 0)
 			  store_frame_param (f, Qfullscreen, Qmaximized);
 		      }