diff --git a/tools/cmd/mouse_demo/main.go b/tools/cmd/mouse_demo/main.go
index a12aad226..d48f34a8d 100644
--- a/tools/cmd/mouse_demo/main.go
+++ b/tools/cmd/mouse_demo/main.go
@@ -17,6 +17,7 @@ import (
 
 var _ = fmt.Print
 var debugprintln = tty.DebugPrintln
+var _ = debugprintln
 
 const dnd_accepted_mimes = "text/plain text/uri-list"