diff --git a/Userland/Libraries/LibJS/Heap/HeapFunction.h b/Userland/Libraries/LibJS/Heap/HeapFunction.h
index c357dc16d4a..e39bf876208 100644
--- a/Userland/Libraries/LibJS/Heap/HeapFunction.h
+++ b/Userland/Libraries/LibJS/Heap/HeapFunction.h
@@ -13,7 +13,7 @@
 namespace JS {
 
 template<typename T>
-class HeapFunction final : public JS::Cell {
+class HeapFunction final : public Cell {
     JS_CELL(HeapFunction, Cell);
 
 public:
diff --git a/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.h b/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.h
index 787047d00b3..3b8d4d6f785 100644
--- a/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.h
+++ b/Userland/Libraries/LibJS/Runtime/PromiseResolvingElementFunctions.h
@@ -71,7 +71,7 @@ private:
 
 // 27.2.4.1.3 Promise.all Resolve Element Functions, https://tc39.es/ecma262/#sec-promise.all-resolve-element-functions
 class PromiseAllResolveElementFunction final : public PromiseResolvingElementFunction {
-    JS_OBJECT(PromiseAllResolveElementFunction, NativeFunction);
+    JS_OBJECT(PromiseAllResolveElementFunction, PromiseResolvingElementFunction);
     JS_DECLARE_ALLOCATOR(PromiseAllResolveElementFunction);
 
 public:
@@ -87,7 +87,7 @@ private:
 
 // 27.2.4.2.2 Promise.allSettled Resolve Element Functions, https://tc39.es/ecma262/#sec-promise.allsettled-resolve-element-functions
 class PromiseAllSettledResolveElementFunction final : public PromiseResolvingElementFunction {
-    JS_OBJECT(PromiseResolvingFunction, NativeFunction);
+    JS_OBJECT(PromiseAllSettledResolveElementFunction, PromiseResolvingElementFunction);
     JS_DECLARE_ALLOCATOR(PromiseAllSettledResolveElementFunction);
 
 public:
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.h
index 9eccf543ac8..363a02c652a 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.h
@@ -16,7 +16,7 @@
 namespace JS::Temporal {
 
 class PlainTime final : public Object {
-    JS_OBJECT(PlainDateTime, Object);
+    JS_OBJECT(PlainTime, Object);
     JS_DECLARE_ALLOCATOR(PlainTime);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Crypto/CryptoKey.h b/Userland/Libraries/LibWeb/Crypto/CryptoKey.h
index c118be95793..ee4e8260cb3 100644
--- a/Userland/Libraries/LibWeb/Crypto/CryptoKey.h
+++ b/Userland/Libraries/LibWeb/Crypto/CryptoKey.h
@@ -69,7 +69,7 @@ private:
 
 // https://w3c.github.io/webcrypto/#ref-for-dfn-CryptoKeyPair-2
 class CryptoKeyPair : public JS::Object {
-    JS_OBJECT(CryptoKeyPair, Object);
+    JS_OBJECT(CryptoKeyPair, JS::Object);
     JS_DECLARE_ALLOCATOR(CryptoKeyPair);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.h
index 1504144ad4f..64ef0aa308a 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/HTTP/Responses.h
@@ -238,7 +238,7 @@ private:
 
 // https://fetch.spec.whatwg.org/#concept-filtered-response-basic
 class BasicFilteredResponse final : public FilteredResponse {
-    JS_CELL(OpaqueRedirectFilteredResponse, FilteredResponse);
+    JS_CELL(BasicFilteredResponse, FilteredResponse);
     JS_DECLARE_ALLOCATOR(BasicFilteredResponse);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Fetch/Infrastructure/IncrementalReadLoopReadRequest.h b/Userland/Libraries/LibWeb/Fetch/Infrastructure/IncrementalReadLoopReadRequest.h
index 220617f18bd..2eb8b6c4495 100644
--- a/Userland/Libraries/LibWeb/Fetch/Infrastructure/IncrementalReadLoopReadRequest.h
+++ b/Userland/Libraries/LibWeb/Fetch/Infrastructure/IncrementalReadLoopReadRequest.h
@@ -13,7 +13,7 @@ namespace Web::Fetch::Infrastructure {
 
 // https://fetch.spec.whatwg.org/#incrementally-read-loop
 class IncrementalReadLoopReadRequest : public Streams::ReadRequest {
-    JS_CELL(IncrementalReadLoopReadRequest, JS::Cell);
+    JS_CELL(IncrementalReadLoopReadRequest, Streams::ReadRequest);
     JS_DECLARE_ALLOCATOR(IncrementalReadLoopReadRequest);
 
 public:
diff --git a/Userland/Libraries/LibWeb/FileAPI/FileReader.h b/Userland/Libraries/LibWeb/FileAPI/FileReader.h
index cf5b64e7826..f069f073e3d 100644
--- a/Userland/Libraries/LibWeb/FileAPI/FileReader.h
+++ b/Userland/Libraries/LibWeb/FileAPI/FileReader.h
@@ -16,7 +16,7 @@ namespace Web::FileAPI {
 
 // https://w3c.github.io/FileAPI/#dfn-filereader
 class FileReader : public DOM::EventTarget {
-    WEB_PLATFORM_OBJECT(FileReader, EventTarget);
+    WEB_PLATFORM_OBJECT(FileReader, DOM::EventTarget);
     JS_DECLARE_ALLOCATOR(FileReader);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrix.h b/Userland/Libraries/LibWeb/Geometry/DOMMatrix.h
index 923fb13495f..1fbb7ffa57b 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrix.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrix.h
@@ -15,7 +15,7 @@ namespace Web::Geometry {
 
 // https://drafts.fxtf.org/geometry/#dommatrix
 class DOMMatrix : public DOMMatrixReadOnly {
-    WEB_PLATFORM_OBJECT(DOMMatrix, Bindings::PlatformObject);
+    WEB_PLATFORM_OBJECT(DOMMatrix, DOMMatrixReadOnly);
     JS_DECLARE_ALLOCATOR(DOMMatrix);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
index f69b9850cda..bfe6cd6ee8b 100644
--- a/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
+++ b/Userland/Libraries/LibWeb/Geometry/DOMMatrixReadOnly.h
@@ -125,6 +125,8 @@ protected:
     DOMMatrixReadOnly(JS::Realm&, DOMMatrixReadOnly const& other);
     explicit DOMMatrixReadOnly(JS::Realm&);
 
+    virtual void initialize(JS::Realm&) override;
+
     // NOTE: The matrix used in the spec is column-major (https://drafts.fxtf.org/geometry/#4x4-abstract-matrix) but Gfx::Matrix4x4 is row-major so we need to transpose the values.
     Gfx::DoubleMatrix4x4 m_matrix { Gfx::DoubleMatrix4x4::identity() };
 
@@ -133,8 +135,6 @@ protected:
 private:
     void initialize_from_create_2d_matrix(double m11, double m12, double m21, double m22, double m41, double m42);
     void initialize_from_create_3d_matrix(double m11, double m12, double m13, double m14, double m21, double m22, double m23, double m24, double m31, double m32, double m33, double m34, double m41, double m42, double m43, double m44);
-
-    virtual void initialize(JS::Realm&) override;
 };
 
 WebIDL::ExceptionOr<void> validate_and_fixup_dom_matrix_2d_init(DOMMatrix2DInit& init);
diff --git a/Userland/Libraries/LibWeb/HTML/AnimatedBitmapDecodedImageData.h b/Userland/Libraries/LibWeb/HTML/AnimatedBitmapDecodedImageData.h
index 0d6ae8a6d6e..3ef104fbfa8 100644
--- a/Userland/Libraries/LibWeb/HTML/AnimatedBitmapDecodedImageData.h
+++ b/Userland/Libraries/LibWeb/HTML/AnimatedBitmapDecodedImageData.h
@@ -12,7 +12,7 @@
 namespace Web::HTML {
 
 class AnimatedBitmapDecodedImageData final : public DecodedImageData {
-    JS_CELL(AnimatedBitmapDecodedImageData, Cell);
+    JS_CELL(AnimatedBitmapDecodedImageData, DecodedImageData);
     JS_DECLARE_ALLOCATOR(AnimatedBitmapDecodedImageData);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
index 9503af86d7c..23a1b56afb8 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
@@ -16,7 +16,7 @@
 namespace Web::HTML {
 
 class EventLoop : public JS::Cell {
-    JS_CELL(EventLoop, Cell);
+    JS_CELL(EventLoop, JS::Cell);
     JS_DECLARE_ALLOCATOR(EventLoop);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/Task.h b/Userland/Libraries/LibWeb/HTML/EventLoop/Task.h
index e16f4adf536..5460dcfc45a 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/Task.h
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/Task.h
@@ -16,7 +16,7 @@ namespace Web::HTML {
 struct UniqueTaskSource;
 
 class Task final : public JS::Cell {
-    JS_CELL(Task, Cell);
+    JS_CELL(Task, JS::Cell);
     JS_DECLARE_ALLOCATOR(Task);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
index 9043afaaf04..32ddf712af8 100644
--- a/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
+++ b/Userland/Libraries/LibWeb/HTML/EventLoop/TaskQueue.h
@@ -13,7 +13,7 @@
 namespace Web::HTML {
 
 class TaskQueue : public JS::Cell {
-    JS_CELL(TaskQueue, Cell);
+    JS_CELL(TaskQueue, JS::Cell);
     JS_DECLARE_ALLOCATOR(TaskQueue);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.h b/Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.h
index f2bace9ae6a..6cd9756ce55 100644
--- a/Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.h
+++ b/Userland/Libraries/LibWeb/HTML/ListOfAvailableImages.h
@@ -17,7 +17,7 @@ namespace Web::HTML {
 
 // https://html.spec.whatwg.org/multipage/images.html#list-of-available-images
 class ListOfAvailableImages : public JS::Cell {
-    JS_CELL(ListOfAvailableImages, Cell);
+    JS_CELL(ListOfAvailableImages, JS::Cell);
     JS_DECLARE_ALLOCATOR(ListOfAvailableImages);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/Location.h b/Userland/Libraries/LibWeb/HTML/Location.h
index 68e2c92d628..4072b4d7372 100644
--- a/Userland/Libraries/LibWeb/HTML/Location.h
+++ b/Userland/Libraries/LibWeb/HTML/Location.h
@@ -18,7 +18,7 @@
 namespace Web::HTML {
 
 class Location final : public Bindings::PlatformObject {
-    JS_OBJECT(Location, Bindings::PlatformObject);
+    WEB_PLATFORM_OBJECT(Location, Bindings::PlatformObject);
     JS_DECLARE_ALLOCATOR(Location);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/ImportMapParseResult.h b/Userland/Libraries/LibWeb/HTML/Scripting/ImportMapParseResult.h
index 971660a40b9..e21c6346e42 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/ImportMapParseResult.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/ImportMapParseResult.h
@@ -18,7 +18,7 @@ namespace Web::HTML {
 class ImportMapParseResult
     : public JS::Cell
     , public JS::Script::HostDefined {
-    JS_CELL(Script, JS::Cell);
+    JS_CELL(ImportMapParseResult, JS::Cell);
     JS_DECLARE_ALLOCATOR(ImportMapParseResult);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/Scripting/ModuleMap.h b/Userland/Libraries/LibWeb/HTML/Scripting/ModuleMap.h
index 65d4a473dc4..a6c805605e3 100644
--- a/Userland/Libraries/LibWeb/HTML/Scripting/ModuleMap.h
+++ b/Userland/Libraries/LibWeb/HTML/Scripting/ModuleMap.h
@@ -36,7 +36,7 @@ private:
 
 // https://html.spec.whatwg.org/multipage/webappapis.html#module-map
 class ModuleMap final : public JS::Cell {
-    JS_CELL(ModuleMap, Cell);
+    JS_CELL(ModuleMap, JS::Cell);
     JS_DECLARE_ALLOCATOR(ModuleMap);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/SessionHistoryTraversalQueue.h b/Userland/Libraries/LibWeb/HTML/SessionHistoryTraversalQueue.h
index 1c227dc4018..06e4f1ad4ea 100644
--- a/Userland/Libraries/LibWeb/HTML/SessionHistoryTraversalQueue.h
+++ b/Userland/Libraries/LibWeb/HTML/SessionHistoryTraversalQueue.h
@@ -43,7 +43,7 @@ private:
 
 // https://html.spec.whatwg.org/multipage/document-sequences.html#tn-session-history-traversal-queue
 class SessionHistoryTraversalQueue : public JS::Cell {
-    JS_CELL(SessionHistoryTraversalQueue, Cell);
+    JS_CELL(SessionHistoryTraversalQueue, JS::Cell);
     JS_DECLARE_ALLOCATOR(SessionHistoryTraversalQueue);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/SharedImageRequest.h b/Userland/Libraries/LibWeb/HTML/SharedImageRequest.h
index 094f529c339..c3e1ab4695e 100644
--- a/Userland/Libraries/LibWeb/HTML/SharedImageRequest.h
+++ b/Userland/Libraries/LibWeb/HTML/SharedImageRequest.h
@@ -18,7 +18,7 @@
 namespace Web::HTML {
 
 class SharedImageRequest final : public JS::Cell {
-    JS_CELL(ImageRequest, JS::Cell);
+    JS_CELL(SharedImageRequest, JS::Cell);
     JS_DECLARE_ALLOCATOR(SharedImageRequest);
 
 public:
diff --git a/Userland/Libraries/LibWeb/HTML/WorkerAgent.h b/Userland/Libraries/LibWeb/HTML/WorkerAgent.h
index 694bdd11c3a..24acd7a2a56 100644
--- a/Userland/Libraries/LibWeb/HTML/WorkerAgent.h
+++ b/Userland/Libraries/LibWeb/HTML/WorkerAgent.h
@@ -19,7 +19,7 @@ struct WorkerOptions {
 };
 
 class WorkerAgent : public JS::Cell {
-    JS_CELL(Agent, JS::Cell);
+    JS_CELL(WorkerAgent, JS::Cell);
     JS_DECLARE_ALLOCATOR(WorkerAgent);
 
     WorkerAgent(URL::URL url, WorkerOptions const& options, JS::GCPtr<MessagePort> outside_port, JS::NonnullGCPtr<EnvironmentSettingsObject> outside_settings);
diff --git a/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.h b/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.h
index c938a653d79..b740a299ba2 100644
--- a/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.h
+++ b/Userland/Libraries/LibWeb/IndexedDB/IDBRequest.h
@@ -11,7 +11,7 @@
 namespace Web::IndexedDB {
 
 class IDBRequest : public DOM::EventTarget {
-    WEB_PLATFORM_OBJECT(IDBRequest, EventTarget);
+    WEB_PLATFORM_OBJECT(IDBRequest, DOM::EventTarget);
     JS_DECLARE_ALLOCATOR(IDBRequest);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
index 4c66eb28b6c..5a5ac629fa7 100644
--- a/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
+++ b/Userland/Libraries/LibWeb/Layout/SVGMaskBox.h
@@ -13,7 +13,7 @@
 namespace Web::Layout {
 
 class SVGMaskBox : public SVGGraphicsBox {
-    JS_CELL(SVGMaskBox, SVGBox);
+    JS_CELL(SVGMaskBox, SVGGraphicsBox);
     JS_DECLARE_ALLOCATOR(SVGMaskBox);
 
 public:
diff --git a/Userland/Libraries/LibWeb/MathML/MathMLElement.h b/Userland/Libraries/LibWeb/MathML/MathMLElement.h
index 71964f28e57..9e2fda8e52e 100644
--- a/Userland/Libraries/LibWeb/MathML/MathMLElement.h
+++ b/Userland/Libraries/LibWeb/MathML/MathMLElement.h
@@ -14,7 +14,7 @@ namespace Web::MathML {
 
 class MathMLElement : public DOM::Element
     , public HTML::GlobalEventHandlers {
-    WEB_PLATFORM_OBJECT(MathMLElement, Element);
+    WEB_PLATFORM_OBJECT(MathMLElement, DOM::Element);
     JS_DECLARE_ALLOCATOR(MathMLElement);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Painting/Paintable.h b/Userland/Libraries/LibWeb/Painting/Paintable.h
index 2a76931eec8..6d1b5aa003e 100644
--- a/Userland/Libraries/LibWeb/Painting/Paintable.h
+++ b/Userland/Libraries/LibWeb/Painting/Paintable.h
@@ -45,7 +45,7 @@ enum class HitTestType {
 class Paintable
     : public JS::Cell
     , public TreeNode<Paintable> {
-    JS_CELL(Paintable, Cell);
+    JS_CELL(Paintable, JS::Cell);
 
 public:
     virtual ~Paintable();
diff --git a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
index 2cbcdaaf408..0565808f7ce 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGDecodedImageData.h
@@ -12,7 +12,7 @@
 namespace Web::SVG {
 
 class SVGDecodedImageData final : public HTML::DecodedImageData {
-    JS_CELL(SVGDecodedImageData, Cell);
+    JS_CELL(SVGDecodedImageData, HTML::DecodedImageData);
     JS_DECLARE_ALLOCATOR(SVGDecodedImageData);
 
 public:
diff --git a/Userland/Libraries/LibWeb/SVG/SVGStyleElement.h b/Userland/Libraries/LibWeb/SVG/SVGStyleElement.h
index bc1ae41cd4d..a688b613140 100644
--- a/Userland/Libraries/LibWeb/SVG/SVGStyleElement.h
+++ b/Userland/Libraries/LibWeb/SVG/SVGStyleElement.h
@@ -12,7 +12,7 @@
 namespace Web::SVG {
 
 class SVGStyleElement final : public SVGElement {
-    WEB_PLATFORM_OBJECT(HTMLStyleElement, SVGElement);
+    WEB_PLATFORM_OBJECT(SVGStyleElement, SVGElement);
     JS_DECLARE_ALLOCATOR(SVGStyleElement);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
index 975a67c220c..ea6b9459660 100644
--- a/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
+++ b/Userland/Libraries/LibWeb/Streams/AbstractOperations.cpp
@@ -350,7 +350,7 @@ WebIDL::ExceptionOr<ReadableStreamPair> readable_stream_tee(JS::Realm& realm, Re
 }
 
 struct DefaultStreamTeeParams final : JS::Cell {
-    JS_CELL(TeeParams, JS::Cell);
+    JS_CELL(DefaultStreamTeeParams, JS::Cell);
     JS_DECLARE_ALLOCATOR(DefaultStreamTeeParams);
 
     virtual void visit_edges(Visitor& visitor) override
@@ -378,7 +378,7 @@ JS_DEFINE_ALLOCATOR(DefaultStreamTeeParams);
 
 // https://streams.spec.whatwg.org/#ref-for-read-request③
 class DefaultStreamTeeReadRequest final : public ReadRequest {
-    JS_CELL(DefaultStreamTeeReadRequest, Cell);
+    JS_CELL(DefaultStreamTeeReadRequest, ReadRequest);
     JS_DECLARE_ALLOCATOR(DefaultStreamTeeReadRequest);
 
 public:
@@ -651,7 +651,7 @@ WebIDL::ExceptionOr<ReadableStreamPair> readable_stream_default_tee(JS::Realm& r
 }
 
 struct ByteStreamTeeParams final : JS::Cell {
-    JS_CELL(TeeParams, JS::Cell);
+    JS_CELL(ByteStreamTeeParams, JS::Cell);
     JS_DECLARE_ALLOCATOR(ByteStreamTeeParams);
 
     explicit ByteStreamTeeParams(ReadableStreamReader reader)
@@ -689,7 +689,7 @@ JS_DEFINE_ALLOCATOR(ByteStreamTeeParams);
 
 // https://streams.spec.whatwg.org/#ref-for-read-request④
 class ByteStreamTeeDefaultReadRequest final : public ReadRequest {
-    JS_CELL(ByteStreamTeeDefaultReadRequest, Cell);
+    JS_CELL(ByteStreamTeeDefaultReadRequest, ReadRequest);
     JS_DECLARE_ALLOCATOR(ByteStreamTeeDefaultReadRequest);
 
 public:
@@ -845,7 +845,7 @@ JS_DEFINE_ALLOCATOR(ByteStreamTeeDefaultReadRequest);
 
 // https://streams.spec.whatwg.org/#ref-for-read-into-request②
 class ByteStreamTeeBYOBReadRequest final : public ReadIntoRequest {
-    JS_CELL(ByteStreamTeeBYOBReadRequest, Cell);
+    JS_CELL(ByteStreamTeeBYOBReadRequest, ReadIntoRequest);
     JS_DECLARE_ALLOCATOR(ByteStreamTeeBYOBReadRequest);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
index 4b7bf1e1469..a02522a5001 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.cpp
@@ -119,7 +119,7 @@ void ReadLoopReadRequest::on_error(JS::Value error)
 }
 
 class DefaultReaderReadRequest final : public ReadRequest {
-    JS_CELL(DefaultReaderReadRequest, Cell);
+    JS_CELL(DefaultReaderReadRequest, ReadRequest);
     JS_DECLARE_ALLOCATOR(DefaultReaderReadRequest);
 
 public:
diff --git a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
index e7ca72293cf..cf0209007ee 100644
--- a/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
+++ b/Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h
@@ -32,7 +32,7 @@ public:
 };
 
 class ReadLoopReadRequest final : public ReadRequest {
-    JS_CELL(ReadLoopReadRequest, JS::Cell);
+    JS_CELL(ReadLoopReadRequest, ReadRequest);
     JS_DECLARE_ALLOCATOR(ReadLoopReadRequest);
 
 public:
diff --git a/Userland/Utilities/js.cpp b/Userland/Utilities/js.cpp
index a08fb37a3fe..1e81140d06d 100644
--- a/Userland/Utilities/js.cpp
+++ b/Userland/Utilities/js.cpp
@@ -445,6 +445,8 @@ static ErrorOr<void> repl(JS::Realm& realm)
 }
 
 class ReplConsoleClient final : public JS::ConsoleClient {
+    JS_CELL(ReplConsoleClient, JS::ConsoleClient);
+
 public:
     ReplConsoleClient(JS::Console& console)
         : ConsoleClient(console)