diff --git a/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtoBeamConverter.java b/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtoBeamConverter.java
index d3295b386d15..559b8dd1b518 100644
--- a/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtoBeamConverter.java
+++ b/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtoBeamConverter.java
@@ -505,12 +505,17 @@ public Message apply(Row row) {
 
     // writeObject() needs to be implemented because Descriptor is not serializable.
     private void writeObject(ObjectOutputStream oos) throws IOException {
-      ProtobufUtil.serializeDescriptor(oos, descriptor);
+      String messageFullName = descriptor.getFullName();
+      ProtoDomain protoDomain = ProtoDomain.buildFrom(descriptor);
+      oos.writeObject(protoDomain);
+      oos.writeObject(messageFullName);
     }
 
     // readObject() needs to be implemented because Descriptor is not serializable.
     private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
-      initialize(ProtobufUtil.deserializeDescriptor(ois));
+      ProtoDomain protoDomain = (ProtoDomain) ois.readObject();
+      String messageFullName = (String) ois.readObject();
+      initialize(protoDomain.getDescriptor(messageFullName));
     }
   }
 
diff --git a/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtobufUtil.java b/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtobufUtil.java
index 92ad0de98b18..c54f098be5c2 100644
--- a/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtobufUtil.java
+++ b/sdks/java/extensions/protobuf/src/main/java/org/apache/beam/sdk/extensions/protobuf/ProtobufUtil.java
@@ -22,9 +22,6 @@
 import com.google.protobuf.ExtensionRegistry;
 import com.google.protobuf.ExtensionRegistry.ExtensionInfo;
 import com.google.protobuf.Message;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
 import java.lang.reflect.InvocationTargetException;
 import java.util.HashSet;
 import java.util.Set;
@@ -92,21 +89,6 @@ static void verifyDeterministic(ProtoCoder<?> coder) throws NonDeterministicExce
     }
   }
 
-  static void serializeDescriptor(ObjectOutputStream oos, Descriptor descriptor)
-      throws IOException {
-    String messageFullName = descriptor.getFullName();
-    ProtoDomain protoDomain = ProtoDomain.buildFrom(descriptor);
-    oos.writeObject(protoDomain);
-    oos.writeObject(messageFullName);
-  }
-
-  static Descriptor deserializeDescriptor(ObjectInputStream ois)
-      throws IOException, ClassNotFoundException {
-    ProtoDomain protoDomain = (ProtoDomain) ois.readObject();
-    String messageFullName = (String) ois.readObject();
-    return protoDomain.getDescriptor(messageFullName);
-  }
-
   ////////////////////////////////////////////////////////////////////////////////////////////////
   // Disable construction of utility class
   private ProtobufUtil() {}