diff --git a/test/src/main/java/org/springframework/ws/mock/client/WebServiceMock.java b/test/src/main/java/org/springframework/ws/mock/client/WebServiceMock.java
index 5ca1b2ec..9735265d 100644
--- a/test/src/main/java/org/springframework/ws/mock/client/WebServiceMock.java
+++ b/test/src/main/java/org/springframework/ws/mock/client/WebServiceMock.java
@@ -26,7 +26,6 @@ import org.springframework.core.io.Resource;
 import org.springframework.util.Assert;
 import org.springframework.ws.client.core.WebServiceTemplate;
 import org.springframework.xml.transform.ResourceSource;
-import org.springframework.xml.transform.StringSource;
 
 /**
  * @author Arjen Poutsma
@@ -63,17 +62,6 @@ public abstract class WebServiceMock {
 
     // RequestMatchers
 
-    /**
-     * Expects the given String XML payload.
-     *
-     * @param payload the XML payload
-     * @return the request matcher
-     */
-    public static RequestMatcher payload(String payload) {
-        Assert.notNull(payload, "'payload' must not be null");
-        return new PayloadDiffMatcher(new StringSource(payload));
-    }
-
     /**
      * Expects the given {@link Source} XML payload.
      *
@@ -131,17 +119,6 @@ public abstract class WebServiceMock {
 
     // ResponseCallbacks
 
-    /**
-     * Respond with the given String XML as payload response.
-     *
-     * @param payload the response payload
-     * @return the response callback
-     */
-    public static ResponseCallback withPayload(String payload) {
-        Assert.notNull(payload, "'payload' must not be null");
-        return new PayloadResponseCallback(new StringSource(payload));
-    }
-
     /**
      * Respond with the given {@link Source} XML as payload response.
      *
diff --git a/test/src/test/java/org/springframework/ws/mock/client/WebServiceMockTest.java b/test/src/test/java/org/springframework/ws/mock/client/WebServiceMockTest.java
index c1ee184a..bd29dc9c 100644
--- a/test/src/test/java/org/springframework/ws/mock/client/WebServiceMockTest.java
+++ b/test/src/test/java/org/springframework/ws/mock/client/WebServiceMockTest.java
@@ -19,6 +19,7 @@ package org.springframework.ws.mock.client;
 import java.io.IOException;
 import java.net.URI;
 import javax.xml.namespace.QName;
+import javax.xml.transform.Source;
 import javax.xml.transform.TransformerException;
 
 import org.springframework.ws.WebServiceMessage;
@@ -73,19 +74,19 @@ public class WebServiceMockTest {
 
     @Test
     public void payloadMatch() throws Exception {
-        String request = "<request xmlns='http://example.com'/>";
-        String response = "<response xmlns='http://example.com'/>";
+        Source request = new StringSource("<request xmlns='http://example.com'/>");
+        Source response = new StringSource("<response xmlns='http://example.com'/>");
 
         expect(payload(request)).andRespond(withPayload(response));
 
         StringResult result = new StringResult();
-        template.sendSourceAndReceiveToResult(new StringSource(request), result);
-        assertXMLEqual(result.toString(), response);
+        template.sendSourceAndReceiveToResult(request, result);
+        assertXMLEqual(result.toString(), response.toString());
     }
 
     @Test(expected = AssertionError.class)
     public void payloadNonMatch() throws Exception {
-        String expected = "<request xmlns='http://example.com'/>";
+        Source expected = new StringSource("<request xmlns='http://example.com'/>");
 
         expect(payload(expected));
 
@@ -140,29 +141,29 @@ public class WebServiceMockTest {
 
     @Test
     public void verifyThreadLocalCleanUp() throws Exception {
-        String request = "<request xmlns='http://example.com'/>";
-        String response = "<response xmlns='http://example.com'/>";
+        Source request = new StringSource("<request xmlns='http://example.com'/>");
+        Source response = new StringSource("<response xmlns='http://example.com'/>");
 
         expect(payload(request)).andRespond(withPayload(response));
         expect(payload(request)).andRespond(withPayload(response));
         assertNotNull(MockWebServiceMessageSenderHolder.get());
 
-        template.sendSourceAndReceiveToResult(new StringSource(request), new StringResult());
+        template.sendSourceAndReceiveToResult(request, new StringResult());
         assertNotNull(MockWebServiceMessageSenderHolder.get());
 
-        template.sendSourceAndReceiveToResult(new StringSource(request), new StringResult());
+        template.sendSourceAndReceiveToResult(request, new StringResult());
         assertNull(MockWebServiceMessageSenderHolder.get());
     }
     
     @Test(expected = AssertionError.class)
     public void unexpectedConnection() throws Exception {
-        String request = "<request xmlns='http://example.com'/>";
-        String response = "<response xmlns='http://example.com'/>";
+        Source request = new StringSource("<request xmlns='http://example.com'/>");
+        Source response = new StringSource("<response xmlns='http://example.com'/>");
 
         expect(payload(request)).andRespond(withPayload(response));
 
-        template.sendSourceAndReceiveToResult(new StringSource(request), new StringResult());
-        template.sendSourceAndReceiveToResult(new StringSource(request), new StringResult());
+        template.sendSourceAndReceiveToResult(request, new StringResult());
+        template.sendSourceAndReceiveToResult(request, new StringResult());
     }
 
 
diff --git a/test/src/test/java/org/springframework/ws/mock/client/integration/IntegrationTest.java b/test/src/test/java/org/springframework/ws/mock/client/integration/IntegrationTest.java
index bbc30efe..c8197984 100644
--- a/test/src/test/java/org/springframework/ws/mock/client/integration/IntegrationTest.java
+++ b/test/src/test/java/org/springframework/ws/mock/client/integration/IntegrationTest.java
@@ -16,10 +16,13 @@
 
 package org.springframework.ws.mock.client.integration;
 
+import javax.xml.transform.Source;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.ws.client.core.WebServiceTemplate;
+import org.springframework.xml.transform.StringSource;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -48,10 +51,10 @@ public class IntegrationTest {
 
     @Test
     public void basic() throws Exception {
-        String expectedRequestPayload = "<customerCountRequest xmlns='http://springframework.org/client'>" +
-                "<customerName>John Doe</customerName>" + "</customerCountRequest>";
-        String responsePayload = "<customerCountResponse xmlns='http://springframework.org/client'>" +
-                "<customerCount>10</customerCount>" + "</customerCountResponse>";
+        Source expectedRequestPayload = new StringSource("<customerCountRequest xmlns='http://springframework.org/client'>" +
+                "<customerName>John Doe</customerName>" + "</customerCountRequest>");
+        Source responsePayload = new StringSource("<customerCountResponse xmlns='http://springframework.org/client'>" +
+                "<customerCount>10</customerCount>" + "</customerCountResponse>");
 
         expect(payload(expectedRequestPayload)).andRespond(withPayload(responsePayload));
 
diff --git a/xml/src/main/java/org/springframework/xml/transform/StringSource.java b/xml/src/main/java/org/springframework/xml/transform/StringSource.java
index 2a9fb8ae..ec6a4d04 100644
--- a/xml/src/main/java/org/springframework/xml/transform/StringSource.java
+++ b/xml/src/main/java/org/springframework/xml/transform/StringSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006 the original author or authors.
+ * Copyright 2005-2010 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,13 @@
 
 package org.springframework.xml.transform;
 
+import java.io.InputStream;
+import java.io.Reader;
 import java.io.StringReader;
 import javax.xml.transform.stream.StreamSource;
 
+import org.springframework.util.Assert;
+
 /**
  * Convenient subclass of <code>StreamSource</code> that reads from a <code>StringReader</code>. The string to be read
  * can be set via the constructor.
@@ -28,23 +32,55 @@ import javax.xml.transform.stream.StreamSource;
  */
 public class StringSource extends StreamSource {
 
+    private final String content;
+
     /**
      * Initializes a new instance of the <code>StringSource</code> with the given string content.
      *
      * @param content the content
      */
     public StringSource(String content) {
-        super(new StringReader(content));
+        Assert.notNull(content, "'content' must not be null");
+        this.content = content;
+    }
+
+    @Override
+    public Reader getReader() {
+        return new StringReader(content);
     }
 
     /**
-     * Initializes a new instance of the <code>StringSource</code> with the given string content and system id.
+     * Throws {@link UnsupportedOperationException}.
      *
-     * @param content  the content
-     * @param systemId a string that conforms to the URI syntax
+     * @throws UnsupportedOperationException always
      */
-    public StringSource(String content, String systemId) {
-        super(new StringReader(content), systemId);
+    @Override
+    public void setInputStream(InputStream inputStream) {
+        throw new UnsupportedOperationException("setInputStream is not supported");
     }
 
+    /**
+     * Returns {@code null}.
+     *
+     * @return {@code null}
+     */
+    @Override
+    public InputStream getInputStream() {
+        return null;
+    }
+
+    /**
+     * Throws {@link UnsupportedOperationException}.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    @Override
+    public void setReader(Reader reader) {
+        throw new UnsupportedOperationException("setReader is not supported");
+    }
+
+    @Override
+    public String toString() {
+        return content;
+    }
 }