diff --git a/csharp/src/Google.Protobuf.Test.TestProtos/UnittestSelfreferentialOptions.cs b/csharp/src/Google.Protobuf.Test.TestProtos/UnittestSelfreferentialOptions.cs
new file mode 100644
index 0000000..e466d54
--- /dev/null
+++ b/csharp/src/Google.Protobuf.Test.TestProtos/UnittestSelfreferentialOptions.cs
@@ -0,0 +1,306 @@
+// <auto-generated>
+//     Generated by the protocol buffer compiler.  DO NOT EDIT!
+//     source: unittest_selfreferential_options.proto
+// </auto-generated>
+#pragma warning disable 1591, 0612, 3021
+#region Designer generated code
+
+using pb = global::Google.Protobuf;
+using pbc = global::Google.Protobuf.Collections;
+using pbr = global::Google.Protobuf.Reflection;
+using scg = global::System.Collections.Generic;
+namespace UnitTest.Issues.TestProtos.SelfreferentialOptions {
+
+  /// <summary>Holder for reflection information generated from unittest_selfreferential_options.proto</summary>
+  public static partial class UnittestSelfreferentialOptionsReflection {
+
+    #region Descriptor
+    /// <summary>File descriptor for unittest_selfreferential_options.proto</summary>
+    public static pbr::FileDescriptor Descriptor {
+      get { return descriptor; }
+    }
+    private static pbr::FileDescriptor descriptor;
+
+    static UnittestSelfreferentialOptionsReflection() {
+      byte[] descriptorData = global::System.Convert.FromBase64String(
+          string.Concat(
+            "CiZ1bml0dGVzdF9zZWxmcmVmZXJlbnRpYWxfb3B0aW9ucy5wcm90bxIpcHJv",
+            "dG9idWZfdW5pdHRlc3Rfc2VsZnJlZmVyZW50aWFsX29wdGlvbnMaIGdvb2ds",
+            "ZS9wcm90b2J1Zi9kZXNjcmlwdG9yLnByb3RvIkwKCkZvb09wdGlvbnMSHgoH",
+            "aW50X29wdBgBIAEoBUINyj4KCAHAPgLKPgIIAxITCgNmb28YAiABKAVCBso+",
+            "AxDSCSoJCOgHEICAgIACOjkKC2Jhcl9vcHRpb25zEh0uZ29vZ2xlLnByb3Rv",
+            "YnVmLkZpZWxkT3B0aW9ucxjoByABKAVCBMA+0gk6agoLZm9vX29wdGlvbnMS",
+            "HS5nb29nbGUucHJvdG9idWYuRmllbGRPcHRpb25zGOkHIAEoCzI1LnByb3Rv",
+            "YnVmX3VuaXR0ZXN0X3NlbGZyZWZlcmVudGlhbF9vcHRpb25zLkZvb09wdGlv",
+            "bnM6SwoLZm9vX2ludF9vcHQSNS5wcm90b2J1Zl91bml0dGVzdF9zZWxmcmVm",
+            "ZXJlbnRpYWxfb3B0aW9ucy5Gb29PcHRpb25zGOgHIAEoBTqCAQoLZm9vX2Zv",
+            "b19vcHQSNS5wcm90b2J1Zl91bml0dGVzdF9zZWxmcmVmZXJlbnRpYWxfb3B0",
+            "aW9ucy5Gb29PcHRpb25zGOkHIAEoCzI1LnByb3RvYnVmX3VuaXR0ZXN0X3Nl",
+            "bGZyZWZlcmVudGlhbF9vcHRpb25zLkZvb09wdGlvbnNCNKoCMVVuaXRUZXN0",
+            "Lklzc3Vlcy5UZXN0UHJvdG9zLlNlbGZyZWZlcmVudGlhbE9wdGlvbnM="));
+      descriptor = pbr::FileDescriptor.FromGeneratedCode(descriptorData,
+          new pbr::FileDescriptor[] { global::Google.Protobuf.Reflection.DescriptorReflection.Descriptor, },
+          new pbr::GeneratedClrTypeInfo(null, new pb::Extension[] { UnittestSelfreferentialOptionsExtensions.BarOptions, UnittestSelfreferentialOptionsExtensions.FooOptions, UnittestSelfreferentialOptionsExtensions.FooIntOpt, UnittestSelfreferentialOptionsExtensions.FooFooOpt }, new pbr::GeneratedClrTypeInfo[] {
+            new pbr::GeneratedClrTypeInfo(typeof(global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions), global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions.Parser, new[]{ "IntOpt", "Foo" }, null, null, null, null)
+          }));
+    }
+    #endregion
+
+  }
+  /// <summary>Holder for extension identifiers generated from the top level of unittest_selfreferential_options.proto</summary>
+  public static partial class UnittestSelfreferentialOptionsExtensions {
+    /// <summary>
+    /// Custom field option used on the definition of that field option.
+    /// </summary>
+    public static readonly pb::Extension<global::Google.Protobuf.Reflection.FieldOptions, int> BarOptions =
+      new pb::Extension<global::Google.Protobuf.Reflection.FieldOptions, int>(1000, pb::FieldCodec.ForInt32(8000, 0));
+    public static readonly pb::Extension<global::Google.Protobuf.Reflection.FieldOptions, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions> FooOptions =
+      new pb::Extension<global::Google.Protobuf.Reflection.FieldOptions, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions>(1001, pb::FieldCodec.ForMessage(8010, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions.Parser));
+    public static readonly pb::Extension<global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions, int> FooIntOpt =
+      new pb::Extension<global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions, int>(1000, pb::FieldCodec.ForInt32(8000, 0));
+    public static readonly pb::Extension<global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions> FooFooOpt =
+      new pb::Extension<global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions>(1001, pb::FieldCodec.ForMessage(8010, global::UnitTest.Issues.TestProtos.SelfreferentialOptions.FooOptions.Parser));
+  }
+
+  #region Messages
+  public sealed partial class FooOptions : pb::IExtendableMessage<FooOptions>, pb::IBufferMessage {
+    private static readonly pb::MessageParser<FooOptions> _parser = new pb::MessageParser<FooOptions>(() => new FooOptions());
+    private pb::UnknownFieldSet _unknownFields;
+    private pb::ExtensionSet<FooOptions> _extensions;
+    private pb::ExtensionSet<FooOptions> _Extensions { get { return _extensions; } }
+    private int _hasBits0;
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pb::MessageParser<FooOptions> Parser { get { return _parser; } }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public static pbr::MessageDescriptor Descriptor {
+      get { return global::UnitTest.Issues.TestProtos.SelfreferentialOptions.UnittestSelfreferentialOptionsReflection.Descriptor.MessageTypes[0]; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    pbr::MessageDescriptor pb::IMessage.Descriptor {
+      get { return Descriptor; }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public FooOptions() {
+      OnConstruction();
+    }
+
+    partial void OnConstruction();
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public FooOptions(FooOptions other) : this() {
+      _hasBits0 = other._hasBits0;
+      intOpt_ = other.intOpt_;
+      foo_ = other.foo_;
+      _unknownFields = pb::UnknownFieldSet.Clone(other._unknownFields);
+      _extensions = pb::ExtensionSet.Clone(other._extensions);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public FooOptions Clone() {
+      return new FooOptions(this);
+    }
+
+    /// <summary>Field number for the "int_opt" field.</summary>
+    public const int IntOptFieldNumber = 1;
+    private readonly static int IntOptDefaultValue = 0;
+
+    private int intOpt_;
+    /// <summary>
+    /// Custom field option used in definition of the extension message.
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int IntOpt {
+      get { if ((_hasBits0 & 1) != 0) { return intOpt_; } else { return IntOptDefaultValue; } }
+      set {
+        _hasBits0 |= 1;
+        intOpt_ = value;
+      }
+    }
+    /// <summary>Gets whether the "int_opt" field is set</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool HasIntOpt {
+      get { return (_hasBits0 & 1) != 0; }
+    }
+    /// <summary>Clears the value of the "int_opt" field</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void ClearIntOpt() {
+      _hasBits0 &= ~1;
+    }
+
+    /// <summary>Field number for the "foo" field.</summary>
+    public const int FooFieldNumber = 2;
+    private readonly static int FooDefaultValue = 0;
+
+    private int foo_;
+    /// <summary>
+    /// Custom field option used in definition of the custom option's message.
+    /// </summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int Foo {
+      get { if ((_hasBits0 & 2) != 0) { return foo_; } else { return FooDefaultValue; } }
+      set {
+        _hasBits0 |= 2;
+        foo_ = value;
+      }
+    }
+    /// <summary>Gets whether the "foo" field is set</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool HasFoo {
+      get { return (_hasBits0 & 2) != 0; }
+    }
+    /// <summary>Clears the value of the "foo" field</summary>
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void ClearFoo() {
+      _hasBits0 &= ~2;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override bool Equals(object other) {
+      return Equals(other as FooOptions);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public bool Equals(FooOptions other) {
+      if (ReferenceEquals(other, null)) {
+        return false;
+      }
+      if (ReferenceEquals(other, this)) {
+        return true;
+      }
+      if (IntOpt != other.IntOpt) return false;
+      if (Foo != other.Foo) return false;
+      if (!Equals(_extensions, other._extensions)) {
+        return false;
+      }
+      return Equals(_unknownFields, other._unknownFields);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override int GetHashCode() {
+      int hash = 1;
+      if (HasIntOpt) hash ^= IntOpt.GetHashCode();
+      if (HasFoo) hash ^= Foo.GetHashCode();
+      if (_extensions != null) {
+        hash ^= _extensions.GetHashCode();
+      }
+      if (_unknownFields != null) {
+        hash ^= _unknownFields.GetHashCode();
+      }
+      return hash;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public override string ToString() {
+      return pb::JsonFormatter.ToDiagnosticString(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void WriteTo(pb::CodedOutputStream output) {
+      if (HasIntOpt) {
+        output.WriteRawTag(8);
+        output.WriteInt32(IntOpt);
+      }
+      if (HasFoo) {
+        output.WriteRawTag(16);
+        output.WriteInt32(Foo);
+      }
+      if (_extensions != null) {
+        _extensions.WriteTo(output);
+      }
+      if (_unknownFields != null) {
+        _unknownFields.WriteTo(output);
+      }
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public int CalculateSize() {
+      int size = 0;
+      if (HasIntOpt) {
+        size += 1 + pb::CodedOutputStream.ComputeInt32Size(IntOpt);
+      }
+      if (HasFoo) {
+        size += 1 + pb::CodedOutputStream.ComputeInt32Size(Foo);
+      }
+      if (_extensions != null) {
+        size += _extensions.CalculateSize();
+      }
+      if (_unknownFields != null) {
+        size += _unknownFields.CalculateSize();
+      }
+      return size;
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(FooOptions other) {
+      if (other == null) {
+        return;
+      }
+      if (other.HasIntOpt) {
+        IntOpt = other.IntOpt;
+      }
+      if (other.HasFoo) {
+        Foo = other.Foo;
+      }
+      pb::ExtensionSet.MergeFrom(ref _extensions, other._extensions);
+      _unknownFields = pb::UnknownFieldSet.MergeFrom(_unknownFields, other._unknownFields);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    public void MergeFrom(pb::CodedInputStream input) {
+      input.ReadRawMessage(this);
+    }
+
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
+    void pb::IBufferMessage.InternalMergeFrom(ref pb::ParseContext input) {
+      uint tag;
+      while ((tag = input.ReadTag()) != 0) {
+        switch(tag) {
+          default:
+            if (!pb::ExtensionSet.TryMergeFieldFrom(ref _extensions, ref input)) {
+              _unknownFields = pb::UnknownFieldSet.MergeFieldFrom(_unknownFields, ref input);
+            }
+            break;
+          case 8: {
+            IntOpt = input.ReadInt32();
+            break;
+          }
+          case 16: {
+            Foo = input.ReadInt32();
+            break;
+          }
+        }
+      }
+    }
+
+    public TValue GetExtension<TValue>(pb::Extension<FooOptions, TValue> extension) {
+      return pb::ExtensionSet.Get(ref _extensions, extension);
+    }
+    public pbc::RepeatedField<TValue> GetExtension<TValue>(pb::RepeatedExtension<FooOptions, TValue> extension) {
+      return pb::ExtensionSet.Get(ref _extensions, extension);
+    }
+    public pbc::RepeatedField<TValue> GetOrInitializeExtension<TValue>(pb::RepeatedExtension<FooOptions, TValue> extension) {
+      return pb::ExtensionSet.GetOrInitialize(ref _extensions, extension);
+    }
+    public void SetExtension<TValue>(pb::Extension<FooOptions, TValue> extension, TValue value) {
+      pb::ExtensionSet.Set(ref _extensions, extension, value);
+    }
+    public bool HasExtension<TValue>(pb::Extension<FooOptions, TValue> extension) {
+      return pb::ExtensionSet.Has(ref _extensions, extension);
+    }
+    public void ClearExtension<TValue>(pb::Extension<FooOptions, TValue> extension) {
+      pb::ExtensionSet.Clear(ref _extensions, extension);
+    }
+    public void ClearExtension<TValue>(pb::RepeatedExtension<FooOptions, TValue> extension) {
+      pb::ExtensionSet.Clear(ref _extensions, extension);
+    }
+
+  }
+
+  #endregion
+
+}
+
+#endregion Designer generated code