diff --git a/packages/operators/src/common/object.js b/packages/operators/src/common/object.js
index 51eaa8712..e1183e6ca 100644
--- a/packages/operators/src/common/object.js
+++ b/packages/operators/src/common/object.js
@@ -45,9 +45,9 @@ const metaInstance = {
 };
 
 const metaClass = {
-  keys: { singleArg: true, validTypes: ['object'] },
-  values: { singleArg: true, validTypes: ['object'] },
-  assign: { spreadArgs: true, validTypes: ['array'] },
+  keys: { singleArg: true, validTypes: ['object'], prep },
+  values: { singleArg: true, validTypes: ['object'], prep },
+  assign: { spreadArgs: true, validTypes: ['array'], prep },
   defineProperty: {
     namedArgs: ['on', 'key', 'descriptor'],
     validTypes: ['array', 'object'],
diff --git a/packages/operators/test/common/object.test.js b/packages/operators/test/common/object.test.js
index ecd971d17..d4ebf3078 100644
--- a/packages/operators/test/common/object.test.js
+++ b/packages/operators/test/common/object.test.js
@@ -201,17 +201,15 @@ describe('_object.assign', () => {
         location,
       })
     ).toEqual({ 0: 'a', a: 1, b: 3 });
-  });
-  test('throw', () => {
-    expect(() =>
+    expect(
       object({
         params: [],
         methodName,
         location,
       })
-    ).toThrowErrorMatchingInlineSnapshot(
-      `"Operator Error: _object.assign - Cannot convert undefined or null to object Received: {\\"_object.assign\\":[]} at locationId."`
-    );
+    ).toEqual({});
+  });
+  test('throw', () => {
     expect(() =>
       object({
         params: 'x',