diff --git a/src/events.h b/src/events.h
index 569408c..7a36444 100644
--- a/src/events.h
+++ b/src/events.h
@@ -7,5 +7,6 @@ extern bool next_p;	// next piece flag
 extern bool pause_f;
 extern bool quit;	// quit flag
 extern bool restart;
+extern bool gradient_d;
 
 #endif