diff --git a/lib/model-builder.js b/lib/model-builder.js
index 18acd3fd..98120755 100644
--- a/lib/model-builder.js
+++ b/lib/model-builder.js
@@ -235,7 +235,7 @@ ModelBuilder.prototype.define = function defineClass(className, properties, sett
                 return s;
             };
         } else if(typeof DataType === 'string') {
-            DataType = getSchemaType(DataType);
+            DataType = schema.getSchemaType(DataType);
         }
 
         Object.defineProperty(ModelClass.prototype, attr, {