diff --git a/lib/rb/spec/ThriftSpec.thrift b/lib/rb/spec/ThriftSpec.thrift
index fe5a8aa..f5c8c09 100644
--- a/lib/rb/spec/ThriftSpec.thrift
+++ b/lib/rb/spec/ThriftSpec.thrift
@@ -42,6 +42,38 @@
   1: string greeting = "hello world"
 }
 
+union My_union {
+  1: bool im_true,
+  2: byte a_bite,
+  3: i16 integer16,
+  4: i32 integer32,
+  5: i64 integer64,
+  6: double double_precision,
+  7: string some_characters,
+  8: i32 other_i32
+}
+
+struct Struct_with_union {
+  1: My_union fun_union
+  2: i32 integer32
+  3: string some_characters
+}
+
+enum SomeEnum {
+  ONE
+  TWO
+}
+
+union TestUnion {
+  /**
+   * A doc string
+   */
+  1: string string_field;
+  2: i32 i32_field;
+  3: i32 other_i32_field;
+  4: SomeEnum enum_field;
+}
+
 struct Foo {
   1: i32 simple = 53,
   2: string words = "words",
diff --git a/lib/rb/spec/binary_protocol_accelerated_spec.rb b/lib/rb/spec/binary_protocol_accelerated_spec.rb
index 48c22e4..b8518c8 100644
--- a/lib/rb/spec/binary_protocol_accelerated_spec.rb
+++ b/lib/rb/spec/binary_protocol_accelerated_spec.rb
@@ -20,22 +20,27 @@
 require File.dirname(__FILE__) + '/spec_helper'
 require File.dirname(__FILE__) + '/binary_protocol_spec_shared'
 
-class ThriftBinaryProtocolAcceleratedSpec < Spec::ExampleGroup
-  include Thrift
+if defined? Thrift::BinaryProtocolAccelerated
 
-  describe Thrift::BinaryProtocolAccelerated do
-    # since BinaryProtocolAccelerated should be directly equivalent to 
-    # BinaryProtocol, we don't need any custom specs!
-    it_should_behave_like 'a binary protocol'
+  class ThriftBinaryProtocolAcceleratedSpec < Spec::ExampleGroup
+    include Thrift
 
-    def protocol_class
-      BinaryProtocolAccelerated
+    describe Thrift::BinaryProtocolAccelerated do
+      # since BinaryProtocolAccelerated should be directly equivalent to 
+      # BinaryProtocol, we don't need any custom specs!
+      it_should_behave_like 'a binary protocol'
+
+      def protocol_class
+        BinaryProtocolAccelerated
+      end
+    end
+
+    describe BinaryProtocolAcceleratedFactory do
+      it "should create a BinaryProtocolAccelerated" do
+        BinaryProtocolAcceleratedFactory.new.get_protocol(mock("MockTransport")).should be_instance_of(BinaryProtocolAccelerated)
+      end
     end
   end
-
-  describe BinaryProtocolAcceleratedFactory do
-    it "should create a BinaryProtocolAccelerated" do
-      BinaryProtocolAcceleratedFactory.new.get_protocol(mock("MockTransport")).should be_instance_of(BinaryProtocolAccelerated)
-    end
-  end
-end
+else
+  puts "skipping BinaryProtocolAccelerated spec because it is not defined."
+end
\ No newline at end of file
diff --git a/lib/rb/spec/binary_protocol_spec_shared.rb b/lib/rb/spec/binary_protocol_spec_shared.rb
index 84f5920..28da760 100644
--- a/lib/rb/spec/binary_protocol_spec_shared.rb
+++ b/lib/rb/spec/binary_protocol_spec_shared.rb
@@ -349,9 +349,9 @@
 
     # first block
     firstblock.call(client)
-    
+
     processor.process(serverproto, serverproto)
-    
+
     # second block
     secondblock.call(client)
   ensure
diff --git a/lib/rb/spec/union_spec.rb b/lib/rb/spec/union_spec.rb
new file mode 100644
index 0000000..4835288
--- /dev/null
+++ b/lib/rb/spec/union_spec.rb
@@ -0,0 +1,145 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+require File.dirname(__FILE__) + '/spec_helper'
+
+class ThriftUnionSpec < Spec::ExampleGroup
+  include Thrift
+  include SpecNamespace
+
+  describe Union do
+    it "should return nil value in unset union" do
+      union = My_union.new
+      union.get_set_field.should == nil
+      union.get_value.should == nil
+    end
+
+    it "should set a field and be accessible through get_value and the named field accessor" do
+      union = My_union.new
+      union.integer32 = 25
+      union.get_set_field.should == :integer32
+      union.get_value.should == 25
+      union.integer32.should == 25
+    end
+
+    it "should work correctly when instantiated with static field constructors" do
+      union = My_union.integer32(5)
+      union.get_set_field.should == :integer32
+      union.integer32.should == 5
+    end
+
+    it "should raise for wrong set field" do
+      union = My_union.new
+      union.integer32 = 25
+      lambda { union.some_characters }.should raise_error(RuntimeError, "some_characters is not union's set field.")
+    end
+     
+    it "should not be equal to nil" do
+      union = My_union.new
+      union.should_not == nil
+    end
+     
+    it "should not equate two different unions, i32 vs. string" do
+      union = My_union.new(:integer32, 25)
+      other_union = My_union.new(:some_characters, "blah!")
+      union.should_not == other_union
+    end
+
+    it "should properly reset setfield and setvalue" do
+      union = My_union.new(:integer32, 25)
+      union.get_set_field.should == :integer32
+      union.some_characters = "blah!"
+      union.get_set_field.should == :some_characters
+      union.get_value.should == "blah!"
+      lambda { union.integer32 }.should raise_error(RuntimeError, "integer32 is not union's set field.")
+    end
+
+    it "should not equate two different unions with different values" do
+      union = My_union.new(:integer32, 25)
+      other_union = My_union.new(:integer32, 400)
+      union.should_not == other_union
+    end
+
+    it "should not equate two different unions with different fields" do
+      union = My_union.new(:integer32, 25)
+      other_union = My_union.new(:other_i32, 25)
+      union.should_not == other_union
+    end
+
+    it "should inspect properly" do
+      union = My_union.new(:integer32, 25)
+      union.inspect.should == "<SpecNamespace::My_union integer32: 25>"
+    end
+
+    it "should not allow setting with instance_variable_set" do
+      union = My_union.new(:integer32, 27)
+      union.instance_variable_set(:@some_characters, "hallo!")
+      union.get_set_field.should == :integer32
+      union.get_value.should == 27
+      lambda { union.some_characters }.should raise_error(RuntimeError, "some_characters is not union's set field.")
+    end
+
+    it "should serialize correctly" do
+      trans = Thrift::MemoryBufferTransport.new
+      proto = Thrift::BinaryProtocol.new(trans)
+
+      union = My_union.new(:integer32, 25)
+      union.write(proto)
+
+      other_union = My_union.new(:integer32, 25)
+      other_union.read(proto)
+      other_union.should == union
+    end
+
+    it "should raise when validating unset union" do
+      union = My_union.new
+      lambda { union.validate }.should raise_error(StandardError, "Union fields are not set.")
+
+      other_union = My_union.new(:integer32, 1)
+      lambda { other_union.validate }.should_not raise_error(StandardError, "Union fields are not set.")
+    end
+
+    it "should validate an enum field properly" do
+      union = TestUnion.new(:enum_field, 3)
+      union.get_set_field.should == :enum_field
+      lambda { union.validate }.should raise_error(ProtocolException, "Invalid value of field enum_field!")
+
+      other_union = TestUnion.new(:enum_field, 1)
+      lambda { other_union.validate }.should_not raise_error(ProtocolException, "Invalid value of field enum_field!")
+    end
+
+    it "should properly serialize and match structs with a union" do
+      union = My_union.new(:integer32, 26)
+      swu = Struct_with_union.new(:fun_union => union)
+
+      trans = Thrift::MemoryBufferTransport.new
+      proto = Thrift::CompactProtocol.new(trans)
+
+      swu.write(proto)
+
+      other_union = My_union.new(:some_characters, "hello there")
+      swu2 = Struct_with_union.new(:fun_union => other_union)
+
+      swu2.should_not == swu
+
+      swu2.read(proto)
+      swu2.should == swu
+    end
+  end
+end