diff --git a/lib/rb/lib/thrift/types.rb b/lib/rb/lib/thrift/types.rb
index bc09195..d7d4cec 100644
--- a/lib/rb/lib/thrift/types.rb
+++ b/lib/rb/lib/thrift/types.rb
@@ -26,7 +26,7 @@
   end
 
   def self.check_type(value, type)
-    return unless Thrift.type_checking
+    return unless Thrift.type_checking and not value.nil?
     klasses = case type
               when Types::VOID
                 NilClass
diff --git a/lib/rb/spec/spec_helper.rb b/lib/rb/spec/spec_helper.rb
index 0d4a64e..874ed2d 100644
--- a/lib/rb/spec/spec_helper.rb
+++ b/lib/rb/spec/spec_helper.rb
@@ -21,3 +21,9 @@
     self
   end
 end
+
+Spec::Runner.configure do |configuration|
+  configuration.before(:each) do
+    Thrift.type_checking = true
+  end
+end
diff --git a/lib/rb/spec/types_spec.rb b/lib/rb/spec/types_spec.rb
index d40e492..8a739f7 100644
--- a/lib/rb/spec/types_spec.rb
+++ b/lib/rb/spec/types_spec.rb
@@ -16,12 +16,13 @@
     it "should check types properly" do
       Thrift.type_checking = true
       begin
-        lambda { Thrift.check_type(nil, Types::STOP) }.should raise_error(TypeError)
+        # lambda { Thrift.check_type(nil, Types::STOP) }.should raise_error(TypeError)
+        lambda { Thrift.check_type(3, Types::STOP) }.should raise_error(TypeError)
         lambda { Thrift.check_type(nil, Types::VOID) }.should_not raise_error(TypeError)
         lambda { Thrift.check_type(3, Types::VOID) }.should raise_error(TypeError)
         lambda { Thrift.check_type(true, Types::BOOL) }.should_not raise_error(TypeError)
         lambda { Thrift.check_type(3, Types::BOOL) }.should raise_error(TypeError)
-        lambda { Thrift.check_type(nil, Types::BOOL) }.should raise_error(TypeError)
+        # lambda { Thrift.check_type(nil, Types::BOOL) }.should raise_error(TypeError)
         lambda { Thrift.check_type(42, Types::BYTE) }.should_not raise_error(TypeError)
         lambda { Thrift.check_type(42, Types::I16) }.should_not raise_error(TypeError)
         lambda { Thrift.check_type(42, Types::I32) }.should_not raise_error(TypeError)