diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
index 46a110481b3..acae97f951e 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.cpp
@@ -48,6 +48,12 @@ void visit_edges(JS::Object& object, JS::Cell::Visitor& visitor)
     }
 }
 
+void finalize(JS::Object& object)
+{
+    auto& global_object = HTML::relevant_global_object(object);
+    Detail::s_caches.remove(global_object);
+}
+
 // https://webassembly.github.io/spec/js-api/#dom-webassembly-validate
 bool validate(JS::VM& vm, JS::Handle<WebIDL::BufferSource>& bytes)
 {
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.h b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.h
index 10429f34898..c73d9a22a9d 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.h
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.h
@@ -19,6 +19,7 @@
 namespace Web::WebAssembly {
 
 void visit_edges(JS::Object&, JS::Cell::Visitor&);
+void finalize(JS::Object&);
 
 bool validate(JS::VM&, JS::Handle<WebIDL::BufferSource>& bytes);
 WebIDL::ExceptionOr<JS::Value> compile(JS::VM&, JS::Handle<WebIDL::BufferSource>& bytes);
diff --git a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.idl b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.idl
index c544b408d16..ca421a4df7f 100644
--- a/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.idl
+++ b/Userland/Libraries/LibWeb/WebAssembly/WebAssembly.idl
@@ -7,7 +7,7 @@ dictionary WebAssemblyInstantiatedSource {
 };
 
 // https://webassembly.github.io/spec/js-api/#webassembly-namespace
-[Exposed=*, WithGCVisitor]
+[Exposed=*, WithGCVisitor, WithFinalizer]
 namespace WebAssembly {
     boolean validate(BufferSource bytes);
     Promise<Module> compile(BufferSource bytes);