diff --git a/lsp/src/main/java/workspace/plugins/POPlugin.java b/lsp/src/main/java/workspace/plugins/POPlugin.java
index 1bb12306f..9dc513942 100644
--- a/lsp/src/main/java/workspace/plugins/POPlugin.java
+++ b/lsp/src/main/java/workspace/plugins/POPlugin.java
@@ -25,9 +25,7 @@
 package workspace.plugins;
 
 import java.io.File;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.Vector;
 
 import com.fujitsu.vdmj.lex.Dialect;
@@ -162,7 +160,6 @@ public RPCMessageList getJSONObligations(RPCRequest request, File file)
 		
 		messagehub.clearPluginMessages(this);
 		List<VDMMessage> messages = new Vector<VDMMessage>();
-		Set<File> errFiles = new HashSet<File>();
 		
 		for (ProofObligation po: poGeneratedList)
 		{
@@ -228,14 +225,12 @@ else if (file.isDirectory())
 				}
 				
 				messages.add(new VDMWarning(9000, sb.toString(), po.location));
-				errFiles.add(po.location.file);
 			}
 			
 			if (po.countermessage != null)
 			{
 				json.put("message", "PO #" + po.number + ": " + po.countermessage);
 				messages.add(new VDMWarning(9001, po.countermessage, po.location));
-				errFiles.add(po.location.file);
 			}
 			
 			poList.add(json);
@@ -243,7 +238,7 @@ else if (file.isDirectory())
 		
 		messagehub.addPluginMessages(this, messages);
 		RPCMessageList result = new RPCMessageList(request, poList);
-		result.addAll(messagehub.getDiagnosticResponses(errFiles));
+		result.addAll(messagehub.getDiagnosticResponses());
 		
 		return result;
 	}
diff --git a/lsp/src/test/java/lsp/POGTest.java b/lsp/src/test/java/lsp/POGTest.java
index fadc4fecf..66f854e24 100644
--- a/lsp/src/test/java/lsp/POGTest.java
+++ b/lsp/src/test/java/lsp/POGTest.java
@@ -65,7 +65,7 @@ public void testSL() throws Exception
 				new JSONObject("uri", file.toURI().toString()));
 		
 		RPCMessageList response = handler.request(request);
-		assertEquals(1, response.size());
+		assertEquals(2, response.size());
 
 		dump(response.get(0));
 		assertEquals("non-zero", response.get(0).getPath("result.[0].kind"));
@@ -96,7 +96,7 @@ public void testPP() throws Exception
 				new JSONObject("uri", testdir.toURI().toString()));
 		
 		RPCMessageList response = handler.request(request);
-		assertEquals(1, response.size());
+		assertEquals(2, response.size());
 
 		dump(response.get(0));
 		assertEquals("non-zero", response.get(0).getPath("result.[0].kind"));
@@ -127,7 +127,7 @@ public void testRT() throws Exception
 				new JSONObject("uri", testdir.toURI().toString()));
 		
 		RPCMessageList response = handler.request(request);
-		assertEquals(1, response.size());
+		assertEquals(2, response.size());
 
 		dump(response.get(0));
 		assertEquals("non-zero", response.get(0).getPath("result.[0].kind"));