diff --git a/java/core/src/main/java/com/google/protobuf/Descriptors.java b/java/core/src/main/java/com/google/protobuf/Descriptors.java
index 5374309665be..be7c76a5b52c 100644
--- a/java/core/src/main/java/com/google/protobuf/Descriptors.java
+++ b/java/core/src/main/java/com/google/protobuf/Descriptors.java
@@ -162,7 +162,7 @@ public List<FileDescriptor> getPublicDependencies() {
     }
 
     /** The syntax of the .proto file. */
-    public enum Syntax {
+    enum Syntax {
       UNKNOWN("unknown"),
       PROTO2("proto2"),
       PROTO3("proto3");
@@ -175,7 +175,7 @@ public enum Syntax {
     }
 
     /** Get the syntax of the .proto file. */
-    public Syntax getSyntax() {
+    Syntax getSyntax() {
       if (Syntax.PROTO3.name.equals(proto.getSyntax())) {
         return Syntax.PROTO3;
       }
diff --git a/ruby/src/main/java/com/google/protobuf/jruby/RubyEnumDescriptor.java b/ruby/src/main/java/com/google/protobuf/jruby/RubyEnumDescriptor.java
index 0eb7c939cb00..24c03cd4d9c7 100644
--- a/ruby/src/main/java/com/google/protobuf/jruby/RubyEnumDescriptor.java
+++ b/ruby/src/main/java/com/google/protobuf/jruby/RubyEnumDescriptor.java
@@ -35,7 +35,7 @@
 import com.google.protobuf.DescriptorProtos.EnumDescriptorProto;
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
-import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.LegacyDescriptorsUtil.LegacyFileDescriptor;
 import org.jruby.Ruby;
 import org.jruby.RubyClass;
 import org.jruby.RubyModule;
@@ -160,7 +160,7 @@ private RubyModule buildModuleFromDescriptor(ThreadContext context) {
 
     RubyModule enumModule = RubyModule.newModule(runtime);
     boolean defaultValueRequiredButNotFound =
-        descriptor.getFile().getSyntax() == FileDescriptor.Syntax.PROTO3;
+        LegacyFileDescriptor.getSyntax(descriptor.getFile()) == LegacyFileDescriptor.Syntax.PROTO3;
     for (EnumValueDescriptor value : descriptor.getValues()) {
       String name = fixEnumConstantName(value.getName());
       // Make sure it's a valid constant name before trying to create it
diff --git a/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java b/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
index bc1fe0cbe64d..50f42cfa7056 100644
--- a/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
+++ b/ruby/src/main/java/com/google/protobuf/jruby/RubyFieldDescriptor.java
@@ -33,7 +33,7 @@
 package com.google.protobuf.jruby;
 
 import com.google.protobuf.Descriptors.FieldDescriptor;
-import com.google.protobuf.Descriptors.FileDescriptor;
+import com.google.protobuf.LegacyDescriptorsUtil.LegacyFileDescriptor;
 import org.jruby.*;
 import org.jruby.anno.JRubyClass;
 import org.jruby.anno.JRubyMethod;
@@ -234,7 +234,8 @@ public IRubyObject setValue(ThreadContext context, IRubyObject message, IRubyObj
   protected void setDescriptor(
       ThreadContext context, FieldDescriptor descriptor, RubyDescriptorPool pool) {
     if (descriptor.isRequired()
-        && descriptor.getFile().getSyntax() == FileDescriptor.Syntax.PROTO3) {
+        && LegacyFileDescriptor.getSyntax(descriptor.getFile())
+            == LegacyFileDescriptor.Syntax.PROTO3) {
       throw Utils.createTypeError(
           context,
           descriptor.getName()
diff --git a/ruby/src/main/java/com/google/protobuf/jruby/RubyFileDescriptor.java b/ruby/src/main/java/com/google/protobuf/jruby/RubyFileDescriptor.java
index 972510b0223f..650480684f7b 100644
--- a/ruby/src/main/java/com/google/protobuf/jruby/RubyFileDescriptor.java
+++ b/ruby/src/main/java/com/google/protobuf/jruby/RubyFileDescriptor.java
@@ -33,8 +33,9 @@
 package com.google.protobuf.jruby;
 
 import com.google.protobuf.Descriptors.FileDescriptor;
-import com.google.protobuf.Descriptors.FileDescriptor.Syntax.*;
 import com.google.protobuf.Descriptors.GenericDescriptor;
+import com.google.protobuf.LegacyDescriptorsUtil.LegacyFileDescriptor;
+import com.google.protobuf.LegacyDescriptorsUtil.LegacyFileDescriptor.Syntax.*;
 import org.jruby.*;
 import org.jruby.anno.JRubyClass;
 import org.jruby.anno.JRubyMethod;
@@ -95,7 +96,7 @@ public IRubyObject getName(ThreadContext context) {
    */
   @JRubyMethod(name = "syntax")
   public IRubyObject getSyntax(ThreadContext context) {
-    switch (fileDescriptor.getSyntax()) {
+    switch (LegacyFileDescriptor.getSyntax(fileDescriptor)) {
       case PROTO2:
         return context.runtime.newSymbol("proto2");
       case PROTO3:
diff --git a/ruby/src/main/java/com/google/protobuf/jruby/RubyMessage.java b/ruby/src/main/java/com/google/protobuf/jruby/RubyMessage.java
index dc76e2d4c047..0213fbc029e0 100644
--- a/ruby/src/main/java/com/google/protobuf/jruby/RubyMessage.java
+++ b/ruby/src/main/java/com/google/protobuf/jruby/RubyMessage.java
@@ -38,10 +38,10 @@
 import com.google.protobuf.Descriptors.EnumDescriptor;
 import com.google.protobuf.Descriptors.EnumValueDescriptor;
 import com.google.protobuf.Descriptors.FieldDescriptor;
-import com.google.protobuf.Descriptors.FileDescriptor;
 import com.google.protobuf.Descriptors.OneofDescriptor;
 import com.google.protobuf.DynamicMessage;
 import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.LegacyDescriptorsUtil.LegacyFileDescriptor;
 import com.google.protobuf.Message;
 import com.google.protobuf.UnknownFieldSet;
 import com.google.protobuf.util.JsonFormat;
@@ -73,7 +73,8 @@ public RubyMessage(Ruby runtime, RubyClass klazz, Descriptor descriptor) {
     this.builder = DynamicMessage.newBuilder(descriptor);
     this.fields = new HashMap<FieldDescriptor, IRubyObject>();
     this.oneofCases = new HashMap<OneofDescriptor, FieldDescriptor>();
-    this.proto3 = descriptor.getFile().getSyntax() == FileDescriptor.Syntax.PROTO3;
+    this.proto3 =
+        LegacyFileDescriptor.getSyntax(descriptor.getFile()) == LegacyFileDescriptor.Syntax.PROTO3;
   }
 
   /*