diff --git a/source/java/org/alfresco/repo/web/scripts/replication/ReplicationDefinitionsPost.java b/source/java/org/alfresco/repo/web/scripts/replication/ReplicationDefinitionsPost.java
index ea8ac3d41b..266be95845 100644
--- a/source/java/org/alfresco/repo/web/scripts/replication/ReplicationDefinitionsPost.java
+++ b/source/java/org/alfresco/repo/web/scripts/replication/ReplicationDefinitionsPost.java
@@ -55,9 +55,16 @@ public class ReplicationDefinitionsPost extends AbstractReplicationWebscript
            if(! json.has("description"))
               throw new WebScriptException(Status.STATUS_BAD_REQUEST, "description is required but wasn't supplied");
            
-           // Create
+           // Ensure one doesn't already exist with that name
+           String name = json.getString("name"); 
+           if(replicationService.loadReplicationDefinition(name) != null)
+           {
+              throw new WebScriptException(Status.STATUS_BAD_REQUEST, "A replication definition already exists with that name");
+           }
+           
+           // Create the definition
            replicationDefinition = replicationService.createReplicationDefinition(
-                 json.getString("name"), json.getString("description")
+                 name, json.getString("description")
            );
            
            // Set the extra parts
diff --git a/source/java/org/alfresco/repo/web/scripts/replication/ReplicationRestApiTest.java b/source/java/org/alfresco/repo/web/scripts/replication/ReplicationRestApiTest.java
index 10e58c7459..9f35937c28 100644
--- a/source/java/org/alfresco/repo/web/scripts/replication/ReplicationRestApiTest.java
+++ b/source/java/org/alfresco/repo/web/scripts/replication/ReplicationRestApiTest.java
@@ -818,9 +818,25 @@ public class ReplicationRestApiTest extends BaseWebScriptTest
        // Ensure we can't create with a duplicate name
        json = new JSONObject();
        json.put("name", "Test");
+       json.put("description", "New Duplicate");
+       json.put("targetName", "New Duplicate Target");
        
        response = sendRequest(new PostRequest(URL_DEFINITIONS, json.toString(), JSON), Status.STATUS_BAD_REQUEST);
        assertEquals(Status.STATUS_BAD_REQUEST, response.getStatus());
+       
+       // Ensure that even though we got BAD REQUEST back, nothing changed
+       rd = replicationService.loadReplicationDefinition("New Definition");
+       assertEquals("New Definition", rd.getReplicationName());
+       assertEquals("Testing", rd.getDescription());
+       assertEquals(ActionStatus.New, rd.getExecutionStatus());
+       assertEquals(null, rd.getExecutionStartDate());
+       assertEquals(null, rd.getExecutionEndDate());
+       assertEquals(null, rd.getExecutionFailureMessage());
+       assertEquals(null, rd.getLocalTransferReport());
+       assertEquals(null, rd.getRemoteTransferReport());
+       assertEquals(null, rd.getTargetName());
+       assertEquals(0, rd.getPayload().size());
+       assertEquals(true, rd.isEnabled());
     }
     
     public void testReplicationDefinitionPut() throws Exception