diff --git a/test/unittests/value-serializer-unittest.cc b/test/unittests/value-serializer-unittest.cc
index 9f49c6498a..8f921ab11b 100644
--- a/test/unittests/value-serializer-unittest.cc
+++ b/test/unittests/value-serializer-unittest.cc
@@ -1866,21 +1866,24 @@ TEST_F(ValueSerializerTest, DecodeArrayBufferOOM) {
   Isolate::CreateParams params;
   params.array_buffer_allocator = &allocator;
   Isolate* isolate = Isolate::New(params);
-  Isolate::Scope isolate_scope(isolate);
-  HandleScope handle_scope(isolate);
-  Local<Context> context = Context::New(isolate);
-  Context::Scope context_scope(context);
-  TryCatch try_catch(isolate);
+  {
+    Isolate::Scope isolate_scope(isolate);
+    HandleScope handle_scope(isolate);
+    Local<Context> context = Context::New(isolate);
+    Context::Scope context_scope(context);
+    TryCatch try_catch(isolate);
 
-  const std::vector<uint8_t> data = {0xff, 0x09, 0x3f, 0x00, 0x42,
-                                     0x03, 0x00, 0x80, 0xff, 0x00};
-  ValueDeserializer deserializer(isolate, &data[0],
-                                 static_cast<int>(data.size()), nullptr);
-  deserializer.SetSupportsLegacyWireFormat(true);
-  ASSERT_TRUE(deserializer.ReadHeader(context).FromMaybe(false));
-  ASSERT_FALSE(try_catch.HasCaught());
-  EXPECT_TRUE(deserializer.ReadValue(context).IsEmpty());
-  EXPECT_TRUE(try_catch.HasCaught());
+    const std::vector<uint8_t> data = {0xff, 0x09, 0x3f, 0x00, 0x42,
+                                       0x03, 0x00, 0x80, 0xff, 0x00};
+    ValueDeserializer deserializer(isolate, &data[0],
+                                   static_cast<int>(data.size()), nullptr);
+    deserializer.SetSupportsLegacyWireFormat(true);
+    ASSERT_TRUE(deserializer.ReadHeader(context).FromMaybe(false));
+    ASSERT_FALSE(try_catch.HasCaught());
+    EXPECT_TRUE(deserializer.ReadValue(context).IsEmpty());
+    EXPECT_TRUE(try_catch.HasCaught());
+  }
+  isolate->Dispose();
 }
 
 // Includes an ArrayBuffer wrapper marked for transfer from the serialization
diff --git a/tools/memory/lsan/suppressions.txt b/tools/memory/lsan/suppressions.txt
index 36e59ecd51..f5c73935be 100644
--- a/tools/memory/lsan/suppressions.txt
+++ b/tools/memory/lsan/suppressions.txt
@@ -14,6 +14,3 @@ leak:v8::internal::compiler::JumpThreading::ApplyForwarding
 # mjsunit
 leak:v8::internal::FuncNameInferrer::FuncNameInferrer
 leak:v8::internal::JSArrayBuffer::SetupAllocatingData
-
-# unittests
-leak:v8::internal::Isolate::FindOrAllocatePerThreadDataForThisThread