diff --git a/src/bidiMapper/modules/script/Realm.ts b/src/bidiMapper/modules/script/Realm.ts
index bafa648c42..2cffe7f5b0 100644
--- a/src/bidiMapper/modules/script/Realm.ts
+++ b/src/bidiMapper/modules/script/Realm.ts
@@ -112,15 +112,18 @@ export abstract class Realm {
         internalIdMap.set(weakLocalObjectReference, uuidv4());
       }
 
-      (deepSerializedValue as any).internalId = internalIdMap.get(
-        weakLocalObjectReference,
-      );
+      (
+        deepSerializedValue as Protocol.Runtime.DeepSerializedValue & {
+          internalId?: string;
+        }
+      ).internalId = internalIdMap.get(weakLocalObjectReference);
       delete deepSerializedValue['weakLocalObjectReference'];
     }
 
     if (
-      (deepSerializedValue as any).type === 'node' &&
-      Object.hasOwn(deepSerializedValue?.value, 'frameId')
+      deepSerializedValue.type === 'node' &&
+      deepSerializedValue.value &&
+      Object.hasOwn(deepSerializedValue.value, 'frameId')
     ) {
       // `frameId` is not needed in BiDi as it is not yet specified.
       delete deepSerializedValue.value['frameId'];
@@ -128,7 +131,7 @@ export abstract class Realm {
 
     // Platform object is a special case. It should have only `{type: object}`
     // without `value` field.
-    if ((deepSerializedValue as any).type === 'platformobject') {
+    if ((deepSerializedValue.type as string) === 'platformobject') {
       return {type: 'object'};
     }
 
diff --git a/tests/script/test_serialization.py b/tests/script/test_serialization.py
index 27500eff4c..0131fed290 100644
--- a/tests/script/test_serialization.py
+++ b/tests/script/test_serialization.py
@@ -18,7 +18,8 @@
 import pytest
 from anys import ANY_STR
 from test_helpers import (ANY_SHARED_ID, ANY_UUID, execute_command, goto_url,
-                          read_JSON_message, send_JSON_command, subscribe)
+                          read_JSON_message, send_JSON_command,
+                          stabilize_key_values, subscribe)
 
 
 def _strip_handle(obj):
@@ -394,8 +395,8 @@ async def test_serialization_internal_id(websocket, context_id):
             "method": "script.evaluate",
             "params": {
                 "expression": "(()=>{"
-                              " const foo={a: []};"
-                              " const bar=[1,2];"
+                              " const foo={a: [], document};"
+                              " const bar=[1,2, document];"
                               " const result={1: foo, 2: foo, 3: bar, 4: bar};"
                               " result.self=result;"
                               " return result;"
@@ -408,26 +409,35 @@ async def test_serialization_internal_id(websocket, context_id):
             }
         })
 
-    internal_id_1 = result["result"]["internalId"]
-    internal_id_2 = result["result"]["value"][0][1]["internalId"]
-    internal_id_3 = result["result"]["value"][2][1]["internalId"]
+    stabilize_key_values(result, ["internalId", "sharedId"])
 
     assert result["result"] == {
         "type": "object",
         "handle": ANY_STR,
-        "internalId": internal_id_1,
+        "internalId": "stable_4",
         "value": [[
             '1', {
                 "type": "object",
                 "value": [["a", {
                     "type": "array",
                     "value": []
-                }]],
-                "internalId": internal_id_2
+                }],
+                          [
+                              'document', {
+                                  'internalId': 'stable_1',
+                                  'sharedId': 'stable_0',
+                                  'type': 'node',
+                                  'value': {
+                                      'childNodeCount': 1,
+                                      'nodeType': 9,
+                                  }
+                              }
+                          ]],
+                "internalId": "stable_2",
             }
         ], ['2', {
             "type": "object",
-            "internalId": internal_id_2
+            "internalId": "stable_2",
         }],
                   [
                       '3', {
@@ -438,16 +448,18 @@ async def test_serialization_internal_id(websocket, context_id):
                           }, {
                               "type": "number",
                               "value": 2
+                          }, {
+                              'internalId': 'stable_1',
+                              'type': 'node',
                           }],
-                          "internalId": internal_id_3
+                          "internalId": "stable_3",
                       }
                   ], ['4', {
                       "type": "array",
-                      "internalId": internal_id_3
-                  }],
-                  ["self", {
+                      "internalId": "stable_3",
+                  }], ["self", {
                       "type": "object",
-                      "internalId": internal_id_1
+                      "internalId": "stable_4",
                   }]],
     }