diff --git a/litestar/_signature/models/msgspec_signature_model.py b/litestar/_signature/models/msgspec_signature_model.py
index 4a1b264606..7dcf01b035 100644
--- a/litestar/_signature/models/msgspec_signature_model.py
+++ b/litestar/_signature/models/msgspec_signature_model.py
@@ -140,7 +140,7 @@ def create(
             f"{fn_name}_signature_model",
             struct_fields,
             bases=(MsgspecSignatureModel,),
-            module=fn_module or "",
+            module=fn_module,
             namespace={
                 "return_annotation": parsed_signature.return_type.annotation,
                 "dependency_name_set": dependency_names,