diff --git a/src/main/java/io/numaproj/numaflow/sourcer/Service.java b/src/main/java/io/numaproj/numaflow/sourcer/Service.java
index 90f6881f..46a9c888 100644
--- a/src/main/java/io/numaproj/numaflow/sourcer/Service.java
+++ b/src/main/java/io/numaproj/numaflow/sourcer/Service.java
@@ -112,6 +112,7 @@ public void onNext(SourceOuterClass.AckRequest request) {
                             .setHandshake(request.getHandshake())
                             .build());
                     handshakeDone = true;
+                    return;
                 }
 
                 SourceOuterClass.Offset offset = request.getRequest().getOffset();