diff --git a/README.md b/README.md
index dcb7bd17d..3680ab05d 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.20.0')
+implementation platform('com.google.cloud:libraries-bom:26.21.0')
 
 implementation 'com.google.cloud:google-cloud-pubsub'
 ```
diff --git a/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java b/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
index 6803e5a43..d0437cb58 100644
--- a/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
+++ b/google-cloud-pubsub/src/main/java/com/google/cloud/pubsub/v1/Publisher.java
@@ -686,7 +686,7 @@ public static final class Builder {
     private static final Duration DEFAULT_TOTAL_TIMEOUT = Duration.ofSeconds(600);
     private static final Duration DEFAULT_INITIAL_RETRY_DELAY = Duration.ofMillis(100);
     private static final Duration DEFAULT_MAX_RETRY_DELAY = Duration.ofSeconds(60);
-    private static final double DEFAULT_MULTIPLIER = 1.3;
+    private static final double DEFAULT_MULTIPLIER = 4;
     static final BatchingSettings DEFAULT_BATCHING_SETTINGS =
         BatchingSettings.newBuilder()
             .setDelayThreshold(DEFAULT_DELAY_THRESHOLD)