diff --git a/google-api-grpc/pom.xml b/google-api-grpc/pom.xml
index 60fa6250ded4..001bdc126d68 100644
--- a/google-api-grpc/pom.xml
+++ b/google-api-grpc/pom.xml
@@ -1006,6 +1006,7 @@
           <show>protected</show>
           <nohelp>true</nohelp>
           <outputDirectory>${project.build.directory}/javadoc</outputDirectory>
+          <splitindex>true</splitindex>
         </configuration>
       </plugin>
     </plugins>