diff --git a/user/pctl/main.c b/user/pctl/main.c
index 8edf89e..991d439 100644
--- a/user/pctl/main.c
+++ b/user/pctl/main.c
@@ -15,6 +15,6 @@ void main(void) {
   if (string_strcmp(cmd, "ls") == 0) {
     pctl_ls();
   } else {
-    uprintf("pctl: unknown command\n");
+    uprintf("pctl: unknown command %s\n", cmd);
   }
 }