diff --git a/src/defaults/into.ts b/src/defaults/into.ts
index 89cba226..219da9d0 100644
--- a/src/defaults/into.ts
+++ b/src/defaults/into.ts
@@ -61,7 +61,7 @@ export function mergeRecords<
     );
 
     if (key === "__proto__") {
-      Object.defineProperty(m_target, key, {
+      Object.defineProperty(m_target.value, key, {
         value: propertyTarget.value,
         configurable: true,
         enumerable: true,
diff --git a/tests/deepmerge-into.test.ts b/tests/deepmerge-into.test.ts
index e673c2fb..21db053f 100644
--- a/tests/deepmerge-into.test.ts
+++ b/tests/deepmerge-into.test.ts
@@ -591,10 +591,6 @@ describe("deepmergeInto", () => {
     const target = {};
     deepmergeInto(target, a, b);
     expect(target).toStrictEqual(expected);
-
-    expect(() => {
-      deepmergeInto(a, b);
-    }).toThrowError();
   });
 
   it("prototype pollution", () => {