diff --git a/lib/rb/lib/thrift/struct.rb b/lib/rb/lib/thrift/struct.rb
index 934d0b7..5a782ca 100644
--- a/lib/rb/lib/thrift/struct.rb
+++ b/lib/rb/lib/thrift/struct.rb
@@ -4,7 +4,7 @@
   module Struct
     def initialize(d={})
       each_field do |fid, type, name, default|
-        instance_variable_set("@#{name}", d[name.to_s] || d[name.intern] || default)
+        instance_variable_set("@#{name}", d[name.to_s] || d[name.intern] || (default.dup rescue default))
       end
     end
 
diff --git a/lib/rb/spec/struct_spec.rb b/lib/rb/spec/struct_spec.rb
index 5e21593..4ae7d42 100644
--- a/lib/rb/spec/struct_spec.rb
+++ b/lib/rb/spec/struct_spec.rb
@@ -37,15 +37,13 @@
   end
 
   it "should not share default values between instances" do
-    pending do
-      begin
-        struct = Foo.new
-        struct.ints << 17
-        Foo.new.ints.should == [1,2,2,3]
-      ensure
-        # ensure no leakage to other tests
-        Foo::FIELDS[4][:default] = [1,2,2,3]
-      end
+    begin
+      struct = Foo.new
+      struct.ints << 17
+      Foo.new.ints.should == [1,2,2,3]
+    ensure
+      # ensure no leakage to other tests
+      Foo::FIELDS[4][:default] = [1,2,2,3]
     end
   end