diff --git a/lib/akami/wsse.rb b/lib/akami/wsse.rb
index 7212861..1a3f30c 100644
--- a/lib/akami/wsse.rb
+++ b/lib/akami/wsse.rb
@@ -91,23 +91,29 @@ def body_attributes
 
     # Returns the XML for a WSSE header.
     def to_xml
+      xml = hash
+
       if signature? and signature.have_document?
-        Gyoku.xml wsse_signature.merge!(hash)
-      elsif username_token? && timestamp?
-        Gyoku.xml wsse_username_token.merge!(wsu_timestamp) {
-          |key, v1, v2| v1.merge!(v2) {
-            |key, v1, v2| v1.merge!(v2)
-          }
-        }
+        xml.merge!(wsse_signature)
       elsif username_token?
-        Gyoku.xml wsse_username_token.merge!(hash)
-      elsif timestamp?
-        Gyoku.xml wsu_timestamp.merge!(hash)
-      else
-        ""
+        xml.merge!(wsse_username_token)
       end
-    end
 
+      if timestamp?
+        xml.merge!(wsu_timestamp) do |key, v1, v2|
+          v1.merge!(v2) do |key, v1, v2|
+            if v1.is_a?(Hash) && v2.is_a?(Hash)
+              v1.merge!(v2)
+            end
+          end
+        end
+        unless xml['wsse:Security'][:order!].nil?
+          xml['wsse:Security'][:order!] << 'wsu:Timestamp'
+        end
+      end
+
+      Gyoku.xml xml
+    end
   private
 
     # Returns a Hash containing wsse:UsernameToken details.
diff --git a/spec/akami/wsse_spec.rb b/spec/akami/wsse_spec.rb
index 2a6c1ec..6752988 100644
--- a/spec/akami/wsse_spec.rb
+++ b/spec/akami/wsse_spec.rb
@@ -29,8 +29,8 @@
     )
   end
 
-  it "contains the namespace for Base64 Encoding type" do 
-    expect(Akami::WSSE::BASE64_URI).to eq( 
+  it "contains the namespace for Base64 Encoding type" do
+    expect(Akami::WSSE::BASE64_URI).to eq(
       "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary"
     )
   end
@@ -243,7 +243,7 @@
       end
     end
 
-    context "whith credentials and timestamp" do
+    context "with credentials and timestamp" do
       before do
         wsse.credentials "username", "password"
         wsse.timestamp = true
@@ -261,6 +261,60 @@
         expect(wsse.to_xml).to include("username", "password")
       end
     end
+
+    context 'with signature' do
+      let(:fixtures_path) {
+        File.join(Bundler.root, 'spec', 'fixtures', 'akami', 'wsse', 'signature')
+      }
+      let(:xml) { fixture('akami/wsse/sample.xml') }
+      let(:cert_path) { File.join(fixtures_path, 'cert.pem') }
+      let(:signature) {
+        Akami::WSSE::Signature.new(
+          Akami::WSSE::Certs.new(
+            cert_file:            cert_path,
+            private_key_file:     cert_path,
+            private_key_password: 'password'
+          )
+        )
+      }
+
+      before do
+        signature.document = xml
+        wsse.signature = signature
+      end
+
+      it 'contains SignedInfo node' do
+        expect(wsse.to_xml).to include('SignedInfo')
+      end
+      it 'contains SignatureValue node' do
+        expect(wsse.to_xml).to include('SignatureValue')
+      end
+      it 'contains KeyInfo node' do
+        expect(wsse.to_xml).to include('KeyInfo')
+      end
+
+      context 'with timestamp' do
+        before do
+          wsse.timestamp = true
+        end
+        it 'contains SignedInfo node' do
+          expect(wsse.to_xml).to include('SignedInfo')
+        end
+        it 'contains SignatureValue node' do
+          expect(wsse.to_xml).to include('SignatureValue')
+        end
+        it 'contains KeyInfo node' do
+          expect(wsse.to_xml).to include('KeyInfo')
+        end
+        it "contains a wsu:Created node" do
+          expect(wsse.to_xml).to include("<wsu:Created>")
+        end
+        it "contains a wsu:Expires node" do
+          expect(wsse.to_xml).to include("<wsu:Expires>")
+        end
+      end
+    end
+
   end
 
 end
diff --git a/spec/fixtures/akami/wsse/sample.xml b/spec/fixtures/akami/wsse/sample.xml
new file mode 100644
index 0000000..b574102
--- /dev/null
+++ b/spec/fixtures/akami/wsse/sample.xml
@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:tns="https://api.example.com/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><env:Body xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="Body-69182b6fd3cdbaa69e00e0bca6c58f6aee1e0c27"><tns:echo>Example</tns:echo></env:Body></env:Envelope>