diff --git a/quickjs.c b/quickjs.c
index 3c10351a..a3cd72a2 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -446,6 +446,7 @@ struct JSString {
     uint32_t hash : 30;
     uint8_t atom_type : 2; /* != 0 if atom, JS_ATOM_TYPE_x */
     uint32_t hash_next; /* atom_index for JS_ATOM_TYPE_SYMBOL */
+    struct JSMapRecord *first_weak_ref;
 #ifdef DUMP_LEAKS
     struct list_head link; /* string list */
 #endif
@@ -43529,11 +43530,23 @@ static void map_hash_resize(JSContext *ctx, JSMapState *s)
     s->record_count_threshold = new_hash_size * 2;
 }
 
+static JSMapRecord **get_first_weak_ref(JSValueConst key) {
+    JSAtomStruct *p;
+    switch (JS_VALUE_GET_TAG(key)) {
+    case JS_TAG_OBJECT:
+        return &JS_VALUE_GET_OBJ(key)->first_weak_ref;
+    case JS_TAG_SYMBOL:
+        p = JS_VALUE_GET_PTR(key);
+        return &p->first_weak_ref;
+    }
+    abort();
+}
+
 static JSMapRecord *map_add_record(JSContext *ctx, JSMapState *s,
                                    JSValueConst key)
 {
     uint32_t h;
-    JSMapRecord *mr;
+    JSMapRecord *mr, **first_weak_ref;
 
     mr = js_malloc(ctx, sizeof(*mr));
     if (!mr)
@@ -43542,10 +43555,10 @@ static JSMapRecord *map_add_record(JSContext *ctx, JSMapState *s,
     mr->map = s;
     mr->empty = FALSE;
     if (s->is_weak) {
-        JSObject *p = JS_VALUE_GET_OBJ(key);
         /* Add the weak reference */
-        mr->next_weak_ref = p->first_weak_ref;
-        p->first_weak_ref = mr;
+        first_weak_ref = get_first_weak_ref(key);
+        mr->next_weak_ref = *first_weak_ref;
+        *first_weak_ref = mr;
     } else {
         JS_DupValue(ctx, key);
     }
@@ -43567,10 +43580,8 @@ static JSMapRecord *map_add_record(JSContext *ctx, JSMapState *s,
 static void delete_weak_ref(JSRuntime *rt, JSMapRecord *mr)
 {
     JSMapRecord **pmr, *mr1;
-    JSObject *p;
 
-    p = JS_VALUE_GET_OBJ(mr->key);
-    pmr = &p->first_weak_ref;
+    pmr = get_first_weak_ref(mr->key);
     for(;;) {
         mr1 = *pmr;
         assert(mr1 != NULL);
@@ -43646,12 +43657,25 @@ static JSValue js_map_set(JSContext *ctx, JSValueConst this_val,
     JSMapState *s = JS_GetOpaque2(ctx, this_val, JS_CLASS_MAP + magic);
     JSMapRecord *mr;
     JSValueConst key, value;
+    JSAtomStruct *p;
 
     if (!s)
         return JS_EXCEPTION;
     key = map_normalize_key(ctx, argv[0]);
-    if (s->is_weak && !JS_IsObject(key))
-        return JS_ThrowTypeErrorNotAnObject(ctx);
+    if (s->is_weak) {
+        switch (JS_VALUE_GET_TAG(key)) {
+        case JS_TAG_OBJECT:
+            break;
+        case JS_TAG_SYMBOL:
+            // Per spec: prohibit symbols registered with Symbol.for()
+            p = JS_VALUE_GET_PTR(key);
+            if (p->atom_type != JS_ATOM_TYPE_GLOBAL_SYMBOL)
+                break;
+            // fallthru
+        default:
+            return JS_ThrowTypeError(ctx, "invalid value used as weak map key");
+        }
+    }
     if (magic & MAGIC_SET)
         value = JS_UNDEFINED;
     else
diff --git a/test262_errors.txt b/test262_errors.txt
index d67a2d88..0f3491ad 100644
--- a/test262_errors.txt
+++ b/test262_errors.txt
@@ -336,38 +336,6 @@ test262/test/built-ins/TypedArrayConstructors/internals/Set/key-is-out-of-bounds
 test262/test/built-ins/TypedArrayConstructors/internals/Set/key-is-out-of-bounds.js:22: strict mode: Test262Error: Reflect.set(sample, "-1", 1) must return true Expected SameValue(«false», «true») to be true (Testing with Float64Array.)
 test262/test/built-ins/TypedArrayConstructors/internals/Set/tonumber-value-detached-buffer.js:39: Test262Error: Expected SameValue(«false», «true») to be true (Testing with Float64Array.)
 test262/test/built-ins/TypedArrayConstructors/internals/Set/tonumber-value-detached-buffer.js:39: strict mode: Test262Error: Expected SameValue(«false», «true») to be true (Testing with Float64Array.)
-test262/test/built-ins/WeakMap/iterable-with-symbol-keys.js:32: TypeError: not an object
-test262/test/built-ins/WeakMap/iterable-with-symbol-keys.js:32: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/delete-entry-with-symbol-key-initial-iterable.js:26: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/delete-entry-with-symbol-key-initial-iterable.js:26: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/delete-entry-with-symbol-key.js:24: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/delete-entry-with-symbol-key.js:24: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/returns-false-when-symbol-key-not-present.js:18: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/delete/returns-false-when-symbol-key-not-present.js:18: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/get/returns-undefined-with-symbol-key.js:28: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/get/returns-undefined-with-symbol-key.js:28: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/get/returns-value-with-symbol-key.js:22: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/get/returns-value-with-symbol-key.js:22: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/has/returns-false-when-symbol-key-not-present.js:20: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/has/returns-false-when-symbol-key-not-present.js:20: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/has/returns-true-when-symbol-key-present.js:19: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/has/returns-true-when-symbol-key-present.js:19: strict mode: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/set/adds-symbol-element.js:17: TypeError: not an object
-test262/test/built-ins/WeakMap/prototype/set/adds-symbol-element.js:17: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/iterable-with-symbol-values.js:24: TypeError: not an object
-test262/test/built-ins/WeakSet/iterable-with-symbol-values.js:24: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/adds-symbol-element.js:17: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/adds-symbol-element.js:17: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/returns-this-symbol.js:18: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/returns-this-symbol.js:18: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate-symbol.js:20: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/add/returns-this-when-ignoring-duplicate-symbol.js:20: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/delete/delete-symbol-entry.js:22: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/delete/delete-symbol-entry.js:22: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/has/returns-false-when-symbol-value-not-present.js:20: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/has/returns-false-when-symbol-value-not-present.js:20: strict mode: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/has/returns-true-when-symbol-value-present.js:17: TypeError: not an object
-test262/test/built-ins/WeakSet/prototype/has/returns-true-when-symbol-value-present.js:17: strict mode: TypeError: not an object
 test262/test/language/expressions/assignment/target-member-computed-reference-null.js:32: Test262Error: Expected a DummyError but got a TypeError
 test262/test/language/expressions/assignment/target-member-computed-reference-null.js:32: strict mode: Test262Error: Expected a DummyError but got a TypeError
 test262/test/language/expressions/assignment/target-member-computed-reference-undefined.js:32: Test262Error: Expected a DummyError but got a TypeError