diff --git a/Libraries/LibJS/Runtime/Shape.cpp b/Libraries/LibJS/Runtime/Shape.cpp
index a5490a6a30..28e10c5cc9 100644
--- a/Libraries/LibJS/Runtime/Shape.cpp
+++ b/Libraries/LibJS/Runtime/Shape.cpp
@@ -31,21 +31,21 @@ namespace JS {
 
 Shape* Shape::create_put_transition(const FlyString& property_name, u8 attributes)
 {
-    auto* new_shape = m_forward_transitions.get(property_name).value_or(nullptr);
-    if (new_shape && new_shape->m_attributes == attributes)
-        return new_shape;
-    new_shape = heap().allocate<Shape>(this, property_name, attributes, TransitionType::Put);
-    m_forward_transitions.set(property_name, new_shape);
+    TransitionKey key { property_name, attributes };
+    if (auto* existing_shape = m_forward_transitions.get(key).value_or(nullptr))
+        return existing_shape;
+    auto* new_shape = heap().allocate<Shape>(this, property_name, attributes, TransitionType::Put);
+    m_forward_transitions.set(key, new_shape);
     return new_shape;
 }
 
 Shape* Shape::create_configure_transition(const FlyString& property_name, u8 attributes)
 {
-    auto* new_shape = m_forward_transitions.get(property_name).value_or(nullptr);
-    if (new_shape && new_shape->m_attributes == attributes)
-        return new_shape;
-    new_shape = heap().allocate<Shape>(this, property_name, attributes, TransitionType::Configure);
-    m_forward_transitions.set(property_name, new_shape);
+    TransitionKey key { property_name, attributes };
+    if (auto* existing_shape = m_forward_transitions.get(key).value_or(nullptr))
+        return existing_shape;
+    auto* new_shape = heap().allocate<Shape>(this, property_name, attributes, TransitionType::Configure);
+    m_forward_transitions.set(key, new_shape);
     return new_shape;
 }
 
diff --git a/Libraries/LibJS/Runtime/Shape.h b/Libraries/LibJS/Runtime/Shape.h
index ff7999db54..70c75fef78 100644
--- a/Libraries/LibJS/Runtime/Shape.h
+++ b/Libraries/LibJS/Runtime/Shape.h
@@ -48,6 +48,17 @@ struct PropertyMetadata {
     u8 attributes { 0 };
 };
 
+struct TransitionKey {
+    FlyString property_name;
+    u8 attributes { 0 };
+
+    bool operator==(const TransitionKey& other) const
+    {
+        return property_name == other.property_name
+            && attributes == other.attributes;
+    }
+};
+
 class Shape final : public Cell {
 public:
     virtual ~Shape() override;
@@ -84,7 +95,7 @@ private:
 
     mutable OwnPtr<HashMap<FlyString, PropertyMetadata>> m_property_table;
 
-    HashMap<FlyString, Shape*> m_forward_transitions;
+    HashMap<TransitionKey, Shape*> m_forward_transitions;
     Shape* m_previous { nullptr };
     FlyString m_property_name;
     u8 m_attributes { 0 };
@@ -93,3 +104,11 @@ private:
 };
 
 }
+
+template<>
+struct AK::Traits<JS::TransitionKey> : public GenericTraits<JS::TransitionKey> {
+    static unsigned hash(const JS::TransitionKey& key)
+    {
+        return pair_int_hash(int_hash(key.attributes), key.property_name.hash());
+    }
+};