diff --git a/update-server-mock/src/main/java/com/intellij/updater/mock/main.kt b/update-server-mock/src/main/java/com/intellij/updater/mock/main.kt
index 902b4fa52fec..4fb8d90b3084 100644
--- a/update-server-mock/src/main/java/com/intellij/updater/mock/main.kt
+++ b/update-server-mock/src/main/java/com/intellij/updater/mock/main.kt
@@ -17,7 +17,7 @@ package com.intellij.updater.mock
 
 fun main(args: Array<String>) {
   if (args.size != 1) {
-    println("usage: java -jar update-server-mock <port>")
+    println("usage: java -jar update-server-mock.jar <port>")
     System.exit(1)
   }