diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/DeployedOnIncludedInExtension.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/DeployedOnIncludedInExtension.java
index e7ffbd3..14ec0da 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/DeployedOnIncludedInExtension.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/DeployedOnIncludedInExtension.java
@@ -14,8 +14,8 @@
 
 package com.googlesource.gerrit.plugins.cookbook;
 
-import com.google.common.collect.ArrayListMultimap;
 import com.google.common.collect.ListMultimap;
+import com.google.common.collect.MultimapBuilder;
 import com.google.gerrit.extensions.config.ExternalIncludedIn;
 
 import java.util.Collection;
@@ -27,7 +27,8 @@
   @Override
   public ListMultimap<String, String> getIncludedIn(String project,
       String commit, Collection<String> tags, Collection<String> branches) {
-    ListMultimap<String, String> m = ArrayListMultimap.create();
+    ListMultimap<String, String> m =
+        MultimapBuilder.hashKeys().arrayListValues().build();
     m.put(PROD, "A");
     m.put(PROD, "B");
     m.put(PROD, "C");