diff --git a/Libraries/LibIDL/Types.h b/Libraries/LibIDL/Types.h
index 9a271a1198f..790b85a9d52 100644
--- a/Libraries/LibIDL/Types.h
+++ b/Libraries/LibIDL/Types.h
@@ -119,7 +119,7 @@ public:
     // https://webidl.spec.whatwg.org/#idl-symbol
     bool is_symbol() const { return is_plain() && m_name == "symbol"; }
 
-    bool is_string() const { return is_plain() && m_name.is_one_of("ByteString", "CSSOMString", "DOMString", "Utf16DOMString", "USVString"); }
+    bool is_string() const { return is_plain() && m_name.is_one_of("ByteString", "CSSOMString", "DOMString", "Utf16DOMString", "USVString", "Utf16USVString"); }
 
     // https://webidl.spec.whatwg.org/#dfn-integer-type
     bool is_integer() const { return is_plain() && m_name.is_one_of("byte", "octet", "short", "unsigned short", "long", "unsigned long", "long long", "unsigned long long"); }
diff --git a/Libraries/LibWeb/WebIDL/AbstractOperations.cpp b/Libraries/LibWeb/WebIDL/AbstractOperations.cpp
index 365f18922fe..10c475316f8 100644
--- a/Libraries/LibWeb/WebIDL/AbstractOperations.cpp
+++ b/Libraries/LibWeb/WebIDL/AbstractOperations.cpp
@@ -244,6 +244,11 @@ JS::ThrowCompletionOr<String> to_usv_string(JS::VM& vm, JS::Value value)
     return TRY(value.to_utf16_string(vm)).to_well_formed_utf8();
 }
 
+JS::ThrowCompletionOr<Utf16String> to_utf16_usv_string(JS::VM& vm, JS::Value value)
+{
+    return TRY(value.to_utf16_string(vm)).to_well_formed();
+}
+
 // https://webidl.spec.whatwg.org/#invoke-a-callback-function
 // https://whatpr.org/webidl/1437.html#invoke-a-callback-function
 template<typename ReturnSteps>
diff --git a/Libraries/LibWeb/WebIDL/AbstractOperations.h b/Libraries/LibWeb/WebIDL/AbstractOperations.h
index d08a968993d..b69da91c0cd 100644
--- a/Libraries/LibWeb/WebIDL/AbstractOperations.h
+++ b/Libraries/LibWeb/WebIDL/AbstractOperations.h
@@ -25,6 +25,7 @@ JS::Completion call_user_object_operation(CallbackType& callback, String const&
 JS::ThrowCompletionOr<String> to_string(JS::VM&, JS::Value);
 JS::ThrowCompletionOr<Utf16String> to_utf16_string(JS::VM&, JS::Value);
 JS::ThrowCompletionOr<String> to_usv_string(JS::VM&, JS::Value);
+JS::ThrowCompletionOr<Utf16String> to_utf16_usv_string(JS::VM&, JS::Value);
 JS::ThrowCompletionOr<String> to_byte_string(JS::VM&, JS::Value);
 
 enum class ExceptionBehavior {
diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index 8fefac9e272..3582cbbfd97 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -426,8 +426,8 @@ static void generate_to_string(SourceGenerator& scoped_generator, ParameterType
         scoped_generator.set("string_suffix", "_string"sv);
     }
 
-    if (parameter.type->name() == "USVString")
-        scoped_generator.set("to_string", "to_usv_string"sv);
+    if (parameter.type->name().is_one_of("USVString"sv, "Utf16USVString"sv))
+        scoped_generator.set("to_string", is_utf16_string ? "to_utf16_usv_string"sv : "to_usv_string"sv);
     else if (parameter.type->name() == "ByteString")
         scoped_generator.set("to_string", "to_byte_string"sv);
     else