diff --git src/simutrans/gui/chat_frame.cc src/simutrans/gui/chat_frame.cc
index 010c72fed..44dc1535b 100644
--- src/simutrans/gui/chat_frame.cc
+++ src/simutrans/gui/chat_frame.cc
@@ -365,7 +365,7 @@ chat_frame_t::chat_frame_t() :
 	set_resizemode(diagonal_resize);
 	reactivate_input = true;
 
-	last_count = 0;
+	last_count = 0xFFFFFFFFul;
 	reset_min_windowsize();
 }