diff --git a/lib/httparty/net_digest_auth.rb b/lib/httparty/net_digest_auth.rb
index e18aef1b..66f5c177 100644
--- a/lib/httparty/net_digest_auth.rb
+++ b/lib/httparty/net_digest_auth.rb
@@ -25,10 +25,13 @@ def authorization_header
           %Q(nonce="#{@response['nonce']}"),
           %Q(uri="#{@path}"),
           %Q(response="#{request_digest}")]
+
         [%Q(cnonce="#{@cnonce}"),
-          %Q(opaque="#{@response['opaque']}"),
           %Q(qop="#{@response['qop']}"),
           %Q(nc="0")].each { |field| header << field } if qop_present?
+
+        header << %Q(opaque="#{@response['opaque']}") if opaque_present?
+
         header
       end
 
@@ -41,6 +44,10 @@ def parse(response_header)
         params
       end
 
+      def opaque_present?
+        @response.has_key?('opaque') and not @response['opaque'].empty?
+      end
+
       def qop_present?
         @response.has_key?('qop') and not @response['qop'].empty?
       end
diff --git a/spec/httparty/net_digest_auth_spec.rb b/spec/httparty/net_digest_auth_spec.rb
index ee4491b4..205e58b3 100644
--- a/spec/httparty/net_digest_auth_spec.rb
+++ b/spec/httparty/net_digest_auth_spec.rb
@@ -13,6 +13,31 @@ def authorization_header
     @digest.authorization_header.join(", ")
   end
 
+
+  context "with an opaque value in the response header" do
+    before do
+      @digest = setup_digest({
+        'www-authenticate' => 'Digest realm="myhost@testrealm.com", opaque="solid"'
+      })
+    end
+
+    it "should set opaque" do
+      authorization_header.should include(%Q(opaque="solid"))
+    end
+  end
+
+  context "without an opaque valid in the response header" do
+    before do
+      @digest = setup_digest({
+        'www-authenticate' => 'Digest realm="myhost@testrealm.com"'
+      })  
+    end
+
+    it "should not set opaque" do
+      authorization_header.should_not include(%Q(opaque=)) 
+    end
+  end
+
   context "with specified quality of protection (qop)" do
     before do
       @digest = setup_digest({