diff --git a/java/carrier/pom.xml b/java/carrier/pom.xml
index 7cb7725b3..87d29f975 100644
--- a/java/carrier/pom.xml
+++ b/java/carrier/pom.xml
@@ -28,6 +28,28 @@
         <targetPath>com/google/i18n/phonenumbers/carrier/testing_data</targetPath>
       </testResource>
     </testResources>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>animal-sniffer-maven-plugin</artifactId>
+        <version>1.15</version>
+        <executions>
+          <execution>
+            <phase>test</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <signature>
+            <groupId>org.codehaus.mojo.signature</groupId>
+            <artifactId>java15</artifactId>
+            <version>1.0</version>
+          </signature>
+        </configuration>
+      </plugin>
+    </plugins>
   </build>
 
   <dependencies>
diff --git a/java/geocoder/pom.xml b/java/geocoder/pom.xml
index 958d5fd18..3e6af7d01 100644
--- a/java/geocoder/pom.xml
+++ b/java/geocoder/pom.xml
@@ -36,6 +36,28 @@
         <targetPath>com/google/i18n/phonenumbers/timezones/testing_data</targetPath>
       </testResource>
     </testResources>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>animal-sniffer-maven-plugin</artifactId>
+        <version>1.15</version>
+        <executions>
+          <execution>
+            <phase>test</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <signature>
+            <groupId>org.codehaus.mojo.signature</groupId>
+            <artifactId>java15</artifactId>
+            <version>1.0</version>
+          </signature>
+        </configuration>
+      </plugin>
+    </plugins>
   </build>
 
   <dependencies>
diff --git a/java/internal/prefixmapper/pom.xml b/java/internal/prefixmapper/pom.xml
index fa4200925..4b0f07620 100644
--- a/java/internal/prefixmapper/pom.xml
+++ b/java/internal/prefixmapper/pom.xml
@@ -23,6 +23,28 @@
         <targetPath>com/google/i18n/phonenumbers/geocoding/testing_data</targetPath>
       </testResource>
     </testResources>
+    <plugins>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>animal-sniffer-maven-plugin</artifactId>
+        <version>1.15</version>
+        <executions>
+          <execution>
+            <phase>test</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <signature>
+            <groupId>org.codehaus.mojo.signature</groupId>
+            <artifactId>java15</artifactId>
+            <version>1.0</version>
+          </signature>
+        </configuration>
+      </plugin>
+    </plugins>
   </build>
 
   <dependencies>
diff --git a/java/libphonenumber/pom.xml b/java/libphonenumber/pom.xml
index 8973e8a33..216ed4e29 100644
--- a/java/libphonenumber/pom.xml
+++ b/java/libphonenumber/pom.xml
@@ -60,6 +60,26 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>org.codehaus.mojo</groupId>
+        <artifactId>animal-sniffer-maven-plugin</artifactId>
+        <version>1.15</version>
+        <executions>
+          <execution>
+            <phase>test</phase>
+            <goals>
+              <goal>check</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <signature>
+            <groupId>org.codehaus.mojo.signature</groupId>
+            <artifactId>java15</artifactId>
+            <version>1.0</version>
+          </signature>
+        </configuration>
+      </plugin>
     </plugins>
   </build>