diff --git a/source/java/org/alfresco/rest/framework/core/ResourceLookupDictionary.java b/source/java/org/alfresco/rest/framework/core/ResourceLookupDictionary.java
index 3d008da84a..cba0fe02f3 100644
--- a/source/java/org/alfresco/rest/framework/core/ResourceLookupDictionary.java
+++ b/source/java/org/alfresco/rest/framework/core/ResourceLookupDictionary.java
@@ -32,7 +32,6 @@ import java.util.Map;
 import java.util.Map.Entry;
 
 import org.alfresco.rest.framework.Api;
-import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
 import org.alfresco.rest.framework.core.exceptions.NotFoundException;
 import org.alfresco.rest.framework.core.exceptions.UnsupportedResourceOperationException;
 import org.apache.commons.lang.StringUtils;
@@ -53,20 +52,20 @@ public class ResourceLookupDictionary implements ResourceLocator
     private ResourceDictionary dictionary;
 
     @Override
-    public ResourceWithMetadata locateEntityResource(Api api, String entityResource, HttpMethod httpMethod) throws InvalidArgumentException, UnsupportedResourceOperationException
+    public ResourceWithMetadata locateEntityResource(Api api, String entityResource, HttpMethod httpMethod) throws NotFoundException, UnsupportedResourceOperationException
     {
         return locateRelationResource(api, entityResource, (String)null, httpMethod);
     }
 
     @Override
-    public ResourceWithMetadata locateRelationPropertyResource(Api api, String entityResource, String relationResource, String property, HttpMethod httpMethod) throws InvalidArgumentException,UnsupportedResourceOperationException
+    public ResourceWithMetadata locateRelationPropertyResource(Api api, String entityResource, String relationResource, String property, HttpMethod httpMethod) throws NotFoundException,UnsupportedResourceOperationException
     {
         String resourceKey = ResourceDictionary.resourceKey(entityResource, relationResource);
         String propertyResourceKey = ResourceDictionary.propertyResourceKey(resourceKey, property);
         Map<String, ResourceWithMetadata> apiResources = dictionary.getAllResources().get(api);
         if (apiResources == null)
         {
-            throw new InvalidArgumentException(InvalidArgumentException.DEFAULT_INVALID_API);
+            throw new NotFoundException(NotFoundException.DEFAULT_MESSAGE_ID);
         }
 
         ResourceWithMetadata resource = apiResources.get(propertyResourceKey);
@@ -78,12 +77,12 @@ public class ResourceLookupDictionary implements ResourceLocator
         }
 
         logger.warn("Unable to locate resource resource for :"+entityResource+" "+relationResource==null?"":relationResource+" "+property==null?"":property);
-        throw new InvalidArgumentException("Unable to locate resource resource for :"+entityResource+" "+(relationResource==null?"":relationResource+" "+property==null?"":property));
+        throw new NotFoundException("Unable to locate resource resource for :"+entityResource+" "+(relationResource==null?"":relationResource+" "+property==null?"":property));
 
     }
 
     @Override
-    public ResourceWithMetadata locateRelationResource(Api api, String entityResource, String relationResource, HttpMethod httpMethod) throws InvalidArgumentException,UnsupportedResourceOperationException
+    public ResourceWithMetadata locateRelationResource(Api api, String entityResource, String relationResource, HttpMethod httpMethod) throws NotFoundException,UnsupportedResourceOperationException
     {
         String resourceKey = ResourceDictionary.resourceKey(entityResource, relationResource);
         if (logger.isDebugEnabled())
@@ -93,7 +92,7 @@ public class ResourceLookupDictionary implements ResourceLocator
         Map<String, ResourceWithMetadata> apiResources = dictionary.getAllResources().get(api);
         if (apiResources == null)
         {
-          throw new InvalidArgumentException(InvalidArgumentException.DEFAULT_INVALID_API);         
+          throw new NotFoundException(NotFoundException.DEFAULT_MESSAGE_ID);
         } 
         ResourceWithMetadata resource = apiResources.get(resourceKey);
         if (resource == null)
@@ -111,7 +110,7 @@ public class ResourceLookupDictionary implements ResourceLocator
               }
           }
           logger.warn("Unable to locate resource resource for :"+entityResource+" "+relationResource==null?"":relationResource);
-          throw new InvalidArgumentException("Unable to locate resource resource for :"+entityResource+" "+(relationResource==null?"":relationResource));      
+          throw new NotFoundException("Unable to locate resource resource for :"+entityResource+" "+(relationResource==null?"":relationResource));
         } 
         else
         {
diff --git a/source/test-java/org/alfresco/rest/framework/tests/core/ExecutionTests.java b/source/test-java/org/alfresco/rest/framework/tests/core/ExecutionTests.java
index da20c068d9..0162613334 100644
--- a/source/test-java/org/alfresco/rest/framework/tests/core/ExecutionTests.java
+++ b/source/test-java/org/alfresco/rest/framework/tests/core/ExecutionTests.java
@@ -259,6 +259,25 @@ public class ExecutionTests extends AbstractContextTest
 
     }
 
+    @Test
+    public void testInvalidUrls() throws IOException
+    {
+        AbstractResourceWebScript executor = (AbstractResourceWebScript) applicationContext.getBean("executorOfGets");
+        executor.setLocator(locator);
+        executor.setResolver(simpleMappingExceptionResolver);
+        executor.setJsonHelper(jsonHelper);
+        Map<String, String> templateVars = new HashMap();
+        templateVars.put("apiScope", "private");
+        templateVars.put("apiVersion", "1");
+        templateVars.put("apiName", "alfrescomock");
+
+        WebScriptResponse response = mockResponse();
+        templateVars.put(ResourceLocator.COLLECTION_RESOURCE, "blah:");
+        executor.execute(api, mockRequest(templateVars, new HashMap<String, List<String>>(1)), response);
+        //Can't find it so a 404
+        verify(response, times(1)).setStatus(HttpServletResponse.SC_NOT_FOUND);
+    }
+
     private WebScriptResponse mockResponse() throws IOException
     {
         WebScriptResponse res = mock(WebScriptResponse.class);
diff --git a/source/test-java/org/alfresco/rest/framework/tests/core/ResourceLocatorTests.java b/source/test-java/org/alfresco/rest/framework/tests/core/ResourceLocatorTests.java
index f19e777405..98f3ad8e46 100644
--- a/source/test-java/org/alfresco/rest/framework/tests/core/ResourceLocatorTests.java
+++ b/source/test-java/org/alfresco/rest/framework/tests/core/ResourceLocatorTests.java
@@ -47,6 +47,7 @@ import org.alfresco.rest.framework.core.ResourceMetadata;
 import org.alfresco.rest.framework.core.ResourceOperation;
 import org.alfresco.rest.framework.core.ResourceWithMetadata;
 import org.alfresco.rest.framework.core.exceptions.InvalidArgumentException;
+import org.alfresco.rest.framework.core.exceptions.NotFoundException;
 import org.alfresco.rest.framework.core.exceptions.UnsupportedResourceOperationException;
 import org.alfresco.rest.framework.resource.EntityResource;
 import org.alfresco.rest.framework.resource.RelationshipResource;
@@ -276,9 +277,9 @@ public class ResourceLocatorTests
         {
             //Tests by passing invalid propery
             collResource = locator.locateResource(api, templateVars, HttpMethod.GET);
-            fail("Should throw an InvalidArgumentException");
+            fail("Should throw an NotFoundException");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -353,9 +354,9 @@ public class ResourceLocatorTests
         try
         {
             entityResource = locator.locateEntityResource(Api.valueOf("alfrescomock", "public", "1"),"sheep", HttpMethod.GET);
-            fail("Should throw an InvalidArgumentException");
+            fail("Should throw an NotFoundException");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -363,9 +364,9 @@ public class ResourceLocatorTests
         try
         {
             entityResource = locator.locateEntityResource(Api.valueOf("alfrescomock", "public", "999"),"sheep", HttpMethod.GET);
-            fail("Should throw an InvalidArgumentException");
+            fail("Should throw an NotFoundException");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -383,9 +384,9 @@ public class ResourceLocatorTests
         try
         {
             aResource = locator.locateEntityResource(api, "sheepnoaction", HttpMethod.GET);
-            fail("Should throw an InvalidArgumentException");
+            fail("Should throw an NotFoundException");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -405,7 +406,7 @@ public class ResourceLocatorTests
             aResource = locator.locateRelationResource(api, "sheepnoaction","v3isaresource", HttpMethod.GET);
             fail("Only available in v3");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -416,7 +417,7 @@ public class ResourceLocatorTests
             aResource = locator.locateRelationResource(v2, "sheepnoaction","v3isaresource", HttpMethod.GET);
             fail("Only available in v3");
         }
-        catch (InvalidArgumentException error)
+        catch (NotFoundException error)
         {
             //this is correct
         }
@@ -474,7 +475,7 @@ public class ResourceLocatorTests
         assertEquals ("sheepnoaction", name);
     }
     
-    @Test(expected=org.alfresco.rest.framework.core.exceptions.InvalidArgumentException.class)
+    @Test(expected=org.alfresco.rest.framework.core.exceptions.NotFoundException.class)
     public void testLocateRelationResource()
     {
         Collection<String> relKeys = Arrays.asList("blacksheep","baaahh");