1 files changed, 4 insertions, 4 deletions
diff --git a/src/fields/Doc.ts b/src/fields/Doc.ts
index f8351c238..7714ce46d 100644
--- a/src/fields/Doc.ts
+++ b/src/fields/Doc.ts
@@ -511,15 +511,15 @@ export namespace Doc {
      */
     export function assign<K extends string>(doc: Doc, fields: Partial<Record<K, Opt<FieldType>>>, skipUndefineds: boolean = false, isInitializing = false) {
         isInitializing && (doc[Initializing] = true);
-        Object.keys(fields).forEach(key => {
-            if (Object.prototype.hasOwnProperty.call(fields.hasOwnProperty, key)) {
+        Object.keys(fields)
+            .filter(key => Object.prototype.hasOwnProperty.call(fields, key))
+            .forEach(key => {
                 const value = (fields as any)[key];
                 if (!skipUndefineds || value !== undefined) {
                     // Do we want to filter out undefineds?
                     doc[key] = value;
                 }
-            }
-        });
+            });
         isInitializing && (doc[Initializing] = false);
         return doc;
     }