diff --git a/redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java b/redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java
index 9886b0c34..9994e01f7 100644
--- a/redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java
+++ b/redisson/src/main/java/org/redisson/pubsub/AsyncSemaphore.java
@@ -122,7 +122,7 @@ public class AsyncSemaphore {
 
     @Override
     public String toString() {
-        return counter;
+        return String.valueOf(counter);
     }