diff --git a/core/src/test/java/org/springframework/ws/server/endpoint/AbstractMessageEndpointTestCase.java b/core/src/test/java/org/springframework/ws/server/endpoint/AbstractMessageEndpointTestCase.java
index 9a07791c..d314f867 100644
--- a/core/src/test/java/org/springframework/ws/server/endpoint/AbstractMessageEndpointTestCase.java
+++ b/core/src/test/java/org/springframework/ws/server/endpoint/AbstractMessageEndpointTestCase.java
@@ -55,7 +55,7 @@ public abstract class AbstractMessageEndpointTestCase extends AbstractEndpointTe
     public void testNoRequestPayload() throws Exception {
         endpoint = createNoRequestPayloadEndpoint();
 
-        MessageContext context = new DefaultMessageContext(new MockWebServiceMessage((StringBuffer) null),
+        MessageContext context = new DefaultMessageContext(new MockWebServiceMessage((StringBuilder) null),
                 new MockWebServiceMessageFactory());
         endpoint.invoke(context);
         assertFalse("Response message created", context.hasResponse());
diff --git a/core/src/test/java/org/springframework/ws/server/endpoint/MarshallingPayloadEndpointTest.java b/core/src/test/java/org/springframework/ws/server/endpoint/MarshallingPayloadEndpointTest.java
index ff563eaa..f14f27ae 100644
--- a/core/src/test/java/org/springframework/ws/server/endpoint/MarshallingPayloadEndpointTest.java
+++ b/core/src/test/java/org/springframework/ws/server/endpoint/MarshallingPayloadEndpointTest.java
@@ -159,7 +159,7 @@ public class MarshallingPayloadEndpointTest {
 
     @Test
     public void testInvokeNoRequest() throws Exception {
-        MockWebServiceMessage request = new MockWebServiceMessage((StringBuffer) null);
+        MockWebServiceMessage request = new MockWebServiceMessage((StringBuilder) null);
         context = new DefaultMessageContext(request, factoryMock);
         AbstractMarshallingPayloadEndpoint endpoint = new AbstractMarshallingPayloadEndpoint() {