diff --git a/lib/schema.js b/lib/schema.js
index cc721b074ee..b02ec83109f 100644
--- a/lib/schema.js
+++ b/lib/schema.js
@@ -938,7 +938,8 @@ Schema.prototype.interpretAsType = function(path, obj, options) {
         }
         if (this._userProvidedOptions.hasOwnProperty('_id')) {
           childSchemaOptions._id = this._userProvidedOptions._id;
-        } else if (Schema.Types.DocumentArray.defaultOptions._id != null) {
+        } else if (Schema.Types.DocumentArray.defaultOptions &&
+            Schema.Types.DocumentArray.defaultOptions._id != null) {
           childSchemaOptions._id = Schema.Types.DocumentArray.defaultOptions._id;
         }