diff --git a/x.c b/x.c
index d284e0e..d34b412 100644
--- a/x.c
+++ b/x.c
@@ -3145,7 +3145,7 @@ reload(int sig)
 void
 usage(void)
 {
-	die("usage: %s [-aiv] [-c class] [-f font] [-g geometry]"
+	die("usage: %s [-aiv] [-A alpha] [-c class] [-f font] [-g geometry]"
 	    " [-n name] [-o file]\n"
 	    "          [-T title] [-t title] [-w windowid]"
 	    " [[-e] command [args ...]]\n"