diff --git a/android/guava/pom.xml b/android/guava/pom.xml
index e990374ebf90..60e45370ea12 100644
--- a/android/guava/pom.xml
+++ b/android/guava/pom.xml
@@ -46,6 +46,7 @@
       <groupId>org.codehaus.mojo</groupId>
       <artifactId>animal-sniffer-annotations</artifactId>
       <version>${animal.sniffer.version}</version>
+      <optional>true</optional>
     </dependency>
     <!-- TODO(cpovirk): does this comment belong on the <dependency> in <profiles>? -->
     <!-- TODO(cpovirk): want this only for dependency plugin but seems not to work there? Maven runs without failure, but the resulting Javadoc is missing the hoped-for inherited text -->
diff --git a/guava/pom.xml b/guava/pom.xml
index df35cea12e5d..a8e404a75094 100644
--- a/guava/pom.xml
+++ b/guava/pom.xml
@@ -46,6 +46,7 @@
       <groupId>org.codehaus.mojo</groupId>
       <artifactId>animal-sniffer-annotations</artifactId>
       <version>${animal.sniffer.version}</version>
+      <optional>true</optional>
     </dependency>
     <!-- TODO(cpovirk): does this comment belong on the <dependency> in <profiles>? -->
     <!-- TODO(cpovirk): want this only for dependency plugin but seems not to work there? Maven runs without failure, but the resulting Javadoc is missing the hoped-for inherited text -->