diff --git a/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java b/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
index 815bb9cf5e0d..409c7321288e 100644
--- a/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
+++ b/google-cloud-clients/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
@@ -256,7 +256,13 @@ public ApiFuture<String> publish(PubsubMessage message) {
     if (!batchesToSend.isEmpty() && orderingKey.isEmpty()) {
       for (final OutstandingBatch batch : batchesToSend) {
         logger.log(Level.FINER, "Scheduling a batch for immediate sending.");
-        publishOutstandingBatch(batch);
+        executor.execute(
+            new Runnable() {
+              @Override
+              public void run() {
+                publishOutstandingBatch(batch);
+              }
+            });
       }
     }