diff --git a/rolluptool/src/classes/TestLREngine.cls b/rolluptool/src/classes/TestLREngine.cls
index f6b442da..013c3ca9 100644
--- a/rolluptool/src/classes/TestLREngine.cls
+++ b/rolluptool/src/classes/TestLREngine.cls
@@ -711,7 +711,7 @@ private class TestLREngine {
                 LREngine.RollupOperation.Last));                 
             System.assert(false, 'Expecting an exception');            
         } catch (Exception e) {
-            System.assertEquals('Master and detail fields must be the same field type (or text based) for First or Last operations', e.getMessage());
+            System.assertEquals('Master and detail fields must be the same field type (or text/Id based) for First or Last operations', e.getMessage());
         }
         try {
             LREngine.Context ctx = 
@@ -724,7 +724,7 @@ private class TestLREngine {
                 LREngine.RollupOperation.First));                 
             System.assert(false, 'Expecting an exception');            
         } catch (Exception e) {
-            System.assertEquals('Master and detail fields must be the same field type (or text based) for First or Last operations', e.getMessage());
+            System.assertEquals('Master and detail fields must be the same field type (or text/Id based) for First or Last operations', e.getMessage());
         }
         // Master and detail field type match
         try {
@@ -997,4 +997,4 @@ private class TestLREngine {
         System.assertEquals(expected1, reloadedAcc3.get(rollupField.master.getName()));
         System.assertEquals(expected2, reloadedAcc4.get(rollupField.master.getName()));
     } 
-}
\ No newline at end of file
+}