diff --git a/Tests/LibJS/test-js.cpp b/Tests/LibJS/test-js.cpp
index e83c1a548d0..5da868d4b14 100644
--- a/Tests/LibJS/test-js.cpp
+++ b/Tests/LibJS/test-js.cpp
@@ -18,7 +18,7 @@ TESTJS_GLOBAL_FUNCTION(is_strict_mode, isStrictMode, 0)
 
 TESTJS_GLOBAL_FUNCTION(can_parse_source, canParseSource)
 {
-    auto source = TRY_OR_DISCARD(vm.argument(0).to_string(global_object));
+    auto source = TRY(vm.argument(0).to_string(global_object));
     auto parser = JS::Parser(JS::Lexer(source));
     parser.parse_program();
     return JS::Value(!parser.has_errors());
@@ -32,22 +32,18 @@ TESTJS_GLOBAL_FUNCTION(run_queued_promise_jobs, runQueuedPromiseJobs)
 
 TESTJS_GLOBAL_FUNCTION(get_weak_set_size, getWeakSetSize)
 {
-    auto* object = TRY_OR_DISCARD(vm.argument(0).to_object(global_object));
-    if (!is<JS::WeakSet>(object)) {
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "WeakSet");
-        return {};
-    }
+    auto* object = TRY(vm.argument(0).to_object(global_object));
+    if (!is<JS::WeakSet>(object))
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "WeakSet");
     auto* weak_set = static_cast<JS::WeakSet*>(object);
     return JS::Value(weak_set->values().size());
 }
 
 TESTJS_GLOBAL_FUNCTION(get_weak_map_size, getWeakMapSize)
 {
-    auto* object = TRY_OR_DISCARD(vm.argument(0).to_object(global_object));
-    if (!is<JS::WeakMap>(object)) {
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "WeakMap");
-        return {};
-    }
+    auto* object = TRY(vm.argument(0).to_object(global_object));
+    if (!is<JS::WeakMap>(object))
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "WeakMap");
     auto* weak_map = static_cast<JS::WeakMap*>(object);
     return JS::Value(weak_map->values().size());
 }
@@ -55,10 +51,8 @@ TESTJS_GLOBAL_FUNCTION(get_weak_map_size, getWeakMapSize)
 TESTJS_GLOBAL_FUNCTION(mark_as_garbage, markAsGarbage)
 {
     auto argument = vm.argument(0);
-    if (!argument.is_string()) {
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAString, argument.to_string_without_side_effects());
-        return {};
-    }
+    if (!argument.is_string())
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAString, argument.to_string_without_side_effects());
 
     auto& variable_name = argument.as_string();
 
@@ -66,21 +60,17 @@ TESTJS_GLOBAL_FUNCTION(mark_as_garbage, markAsGarbage)
     auto outer_environment = vm.execution_context_stack().last_matching([&](auto& execution_context) {
         return execution_context->lexical_environment != nullptr;
     });
-    if (!outer_environment.has_value()) {
-        vm.throw_exception<JS::ReferenceError>(global_object, JS::ErrorType::UnknownIdentifier, variable_name.string());
-        return {};
-    }
+    if (!outer_environment.has_value())
+        return vm.throw_completion<JS::ReferenceError>(global_object, JS::ErrorType::UnknownIdentifier, variable_name.string());
 
     auto reference = vm.resolve_binding(variable_name.string(), outer_environment.value()->lexical_environment);
 
     auto value = reference.get_value(global_object);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return JS::throw_completion(exception->value());
 
-    if (!value.is_object()) {
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObject, String::formatted("Variable with name {}", variable_name.string()));
-        return {};
-    }
+    if (!value.is_object())
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObject, String::formatted("Variable with name {}", variable_name.string()));
 
     vm.heap().uproot_cell(&value.as_object());
     reference.delete_(global_object);
diff --git a/Tests/LibWasm/test-wasm.cpp b/Tests/LibWasm/test-wasm.cpp
index 067ee0258fe..e9243f8f4d8 100644
--- a/Tests/LibWasm/test-wasm.cpp
+++ b/Tests/LibWasm/test-wasm.cpp
@@ -13,16 +13,14 @@ TEST_ROOT("Userland/Libraries/LibWasm/Tests");
 
 TESTJS_GLOBAL_FUNCTION(read_binary_wasm_file, readBinaryWasmFile)
 {
-    auto filename = TRY_OR_DISCARD(vm.argument(0).to_string(global_object));
+    auto filename = TRY(vm.argument(0).to_string(global_object));
     auto file = Core::File::open(filename, Core::OpenMode::ReadOnly);
-    if (file.is_error()) {
-        vm.throw_exception<JS::TypeError>(global_object, file.error().string());
-        return {};
-    }
+    if (file.is_error())
+        return vm.throw_completion<JS::TypeError>(global_object, file.error().string());
     auto contents = file.value()->read_all();
     auto array = JS::Uint8Array::create(global_object, contents.size());
     contents.span().copy_to(array->data());
-    return array;
+    return JS::Value(array);
 }
 
 class WebAssemblyModule final : public JS::Object {
@@ -93,11 +91,9 @@ HashMap<Wasm::Linker::Name, Wasm::ExternValue> WebAssemblyModule::s_spec_test_na
 
 TESTJS_GLOBAL_FUNCTION(parse_webassembly_module, parseWebAssemblyModule)
 {
-    auto* object = TRY_OR_DISCARD(vm.argument(0).to_object(global_object));
-    if (!is<JS::Uint8Array>(object)) {
-        vm.throw_exception<JS::TypeError>(global_object, "Expected a Uint8Array argument to parse_webassembly_module");
-        return {};
-    }
+    auto* object = TRY(vm.argument(0).to_object(global_object));
+    if (!is<JS::Uint8Array>(object))
+        return vm.throw_completion<JS::TypeError>(global_object, "Expected a Uint8Array argument to parse_webassembly_module");
     auto& array = static_cast<JS::Uint8Array&>(*object);
     InputMemoryStream stream { array.data() };
     ScopeGuard handle_stream_error {
@@ -106,15 +102,11 @@ TESTJS_GLOBAL_FUNCTION(parse_webassembly_module, parseWebAssemblyModule)
         }
     };
     auto result = Wasm::Module::parse(stream);
-    if (result.is_error()) {
-        vm.throw_exception<JS::SyntaxError>(global_object, Wasm::parse_error_to_string(result.error()));
-        return {};
-    }
+    if (result.is_error())
+        return vm.throw_completion<JS::SyntaxError>(global_object, Wasm::parse_error_to_string(result.error()));
 
-    if (stream.handle_any_error()) {
-        vm.throw_exception<JS::SyntaxError>(global_object, "Binary stream contained errors");
-        return {};
-    }
+    if (stream.handle_any_error())
+        return vm.throw_completion<JS::SyntaxError>(global_object, "Binary stream contained errors");
 
     HashMap<Wasm::Linker::Name, Wasm::ExternValue> imports;
     auto import_value = vm.argument(1);
@@ -132,22 +124,18 @@ TESTJS_GLOBAL_FUNCTION(parse_webassembly_module, parseWebAssemblyModule)
         }
     }
 
-    return WebAssemblyModule::create(global_object, result.release_value(), imports);
+    return JS::Value(WebAssemblyModule::create(global_object, result.release_value(), imports));
 }
 
 TESTJS_GLOBAL_FUNCTION(compare_typed_arrays, compareTypedArrays)
 {
-    auto* lhs = TRY_OR_DISCARD(vm.argument(0).to_object(global_object));
-    if (!is<JS::TypedArrayBase>(lhs)) {
-        vm.throw_exception<JS::TypeError>(global_object, "Expected a TypedArray");
-        return {};
-    }
+    auto* lhs = TRY(vm.argument(0).to_object(global_object));
+    if (!is<JS::TypedArrayBase>(lhs))
+        return vm.throw_completion<JS::TypeError>(global_object, "Expected a TypedArray");
     auto& lhs_array = static_cast<JS::TypedArrayBase&>(*lhs);
-    auto* rhs = TRY_OR_DISCARD(vm.argument(1).to_object(global_object));
-    if (!is<JS::TypedArrayBase>(rhs)) {
-        vm.throw_exception<JS::TypeError>(global_object, "Expected a TypedArray");
-        return {};
-    }
+    auto* rhs = TRY(vm.argument(1).to_object(global_object));
+    if (!is<JS::TypedArrayBase>(rhs))
+        return vm.throw_completion<JS::TypeError>(global_object, "Expected a TypedArray");
     auto& rhs_array = static_cast<JS::TypedArrayBase&>(*rhs);
     return JS::Value(lhs_array.viewed_array_buffer()->buffer() == rhs_array.viewed_array_buffer()->buffer());
 }
diff --git a/Tests/LibWeb/test-web.cpp b/Tests/LibWeb/test-web.cpp
index 893adab2626..0bd22a29edc 100644
--- a/Tests/LibWeb/test-web.cpp
+++ b/Tests/LibWeb/test-web.cpp
@@ -40,7 +40,7 @@ TESTJS_MAIN_HOOK()
 
 TESTJS_GLOBAL_FUNCTION(load_local_page, loadLocalPage)
 {
-    auto name = TRY_OR_DISCARD(vm.argument(0).to_string(global_object));
+    auto name = TRY(vm.argument(0).to_string(global_object));
 
     // Clear the hooks
     before_initial_load_hooks.clear();
@@ -59,8 +59,7 @@ TESTJS_GLOBAL_FUNCTION(after_initial_page_load, afterInitialPageLoad)
     auto function = vm.argument(0);
     if (!function.is_function()) {
         dbgln("afterInitialPageLoad argument is not a function");
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
-        return {};
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
     }
 
     after_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &vm](auto& page_object) {
@@ -74,8 +73,7 @@ TESTJS_GLOBAL_FUNCTION(before_initial_page_load, beforeInitialPageLoad)
     auto function = vm.argument(0);
     if (!function.is_function()) {
         dbgln("beforeInitialPageLoad argument is not a function");
-        vm.throw_exception<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
-        return {};
+        return vm.throw_completion<JS::TypeError>(global_object, JS::ErrorType::NotAnObjectOfType, "Function");
     }
 
     before_initial_load_hooks.append([fn = JS::make_handle(&function.as_function()), &vm](auto& page_object) {
diff --git a/Userland/Libraries/LibTest/JavaScriptTestRunner.h b/Userland/Libraries/LibTest/JavaScriptTestRunner.h
index 8bc93f63af2..10dfd622648 100644
--- a/Userland/Libraries/LibTest/JavaScriptTestRunner.h
+++ b/Userland/Libraries/LibTest/JavaScriptTestRunner.h
@@ -64,9 +64,9 @@
     } __testjs_register_##fn {};
 
 #define TESTJS_GLOBAL_FUNCTION(function, exposed_name, ...)                    \
-    JS_DECLARE_OLD_NATIVE_FUNCTION(function);                                  \
+    JS_DECLARE_NATIVE_FUNCTION(function);                                      \
     __TESTJS_REGISTER_GLOBAL_FUNCTION(#exposed_name, function, ##__VA_ARGS__); \
-    JS_DEFINE_OLD_NATIVE_FUNCTION(function)
+    JS_DEFINE_NATIVE_FUNCTION(function)
 
 #define TESTJS_MAIN_HOOK()                  \
     struct __TestJS_main_hook {             \
@@ -120,7 +120,7 @@ extern bool g_run_bytecode;
 extern bool g_dump_bytecode;
 extern String g_currently_running_test;
 struct FunctionWithLength {
-    JS::Value (*function)(JS::VM&, JS::GlobalObject&);
+    JS::ThrowCompletionOr<JS::Value> (*function)(JS::VM&, JS::GlobalObject&);
     size_t length { 0 };
 };
 extern HashMap<String, FunctionWithLength> s_exposed_global_functions;
@@ -191,7 +191,7 @@ inline void TestRunnerGlobalObject::initialize_global_object()
     Base::initialize_global_object();
     define_direct_property("global", this, JS::Attribute::Enumerable);
     for (auto& entry : s_exposed_global_functions) {
-        define_old_native_function(
+        define_native_function(
             entry.key, [fn = entry.value.function](auto& vm, auto& global_object) {
                 return fn(vm, global_object);
             },