diff --git a/src/Plugins/SimplnxCore/wrapping/python/simplnxpy.cpp b/src/Plugins/SimplnxCore/wrapping/python/simplnxpy.cpp
index 59ecbf28f1..6f0ac60d26 100644
--- a/src/Plugins/SimplnxCore/wrapping/python/simplnxpy.cpp
+++ b/src/Plugins/SimplnxCore/wrapping/python/simplnxpy.cpp
@@ -561,7 +561,7 @@ PYBIND11_MODULE(simplnx, mod)
           return NumericType::float64;
         }
 
-        std::string dtypeStr = py::str(dtype);
+        std::string dtypeStr = py::str(static_cast<py::object>(dtype));
         throw std::invalid_argument(fmt::format("Unable to convert dtype to NumericType: Unsupported dtype '{}'.", dtypeStr));
       },
       "Convert numpy dtype to simplnx NumericType", "dtype"_a);