diff --git a/sdks/java/extensions/protobuf/build.gradle b/sdks/java/extensions/protobuf/build.gradle
index 1ed48f3cfc1c..4571e7119115 100644
--- a/sdks/java/extensions/protobuf/build.gradle
+++ b/sdks/java/extensions/protobuf/build.gradle
@@ -18,6 +18,7 @@
 
 plugins { id 'org.apache.beam.module' }
 applyJavaNature(
+  enableStrictDependencies: true,
   generatedClassPatterns: [
     /^org\.apache\.beam\.sdk\.extensions\.protobuf\.PayloadMessages/,
     /^org\.apache\.beam\.sdk\.extensions\.protobuf\.Proto2CoderTestMessages/,
@@ -33,13 +34,11 @@ description = "Apache Beam :: SDKs :: Java :: Extensions :: Protobuf"
 ext.summary = "Add support to Apache Beam for Google Protobuf."
 
 dependencies {
+  compile library.java.vendored_bytebuddy_1_10_8
   compile library.java.vendored_guava_26_0_jre
   compile project(path: ":sdks:java:core", configuration: "shadow")
   compile library.java.protobuf_java
   testCompile project(path: ":sdks:java:core", configuration: "shadowTest")
-  testCompile library.java.hamcrest_core
-  testCompile library.java.hamcrest_library
-  testCompile library.java.mockito_core
   testCompile library.java.junit
   testRuntimeOnly library.java.slf4j_jdk14
 }