diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/om/types/BuiltinType.java b/asterix-om/src/main/java/edu/uci/ics/asterix/om/types/BuiltinType.java
index 1e498bc..a70f15b 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/om/types/BuiltinType.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/om/types/BuiltinType.java
@@ -450,6 +450,10 @@
             return "interval";
         }
 
+        @Override
+        public JSONObject toJSON() throws JSONException {
+            return null;
+        }
     };
 
     public final static BuiltinType APOINT = new LowerCaseConstructorType() {
@@ -742,4 +746,4 @@
         throw new AsterixException("No string translation for type: " + str + " .");
     }
 
-}
\ No newline at end of file
+}