diff --git a/src/ObjLoading/StructuredDataDef/Parsing/StructuredDataDefSizeCalculator.h b/src/ObjLoading/StructuredDataDef/Parsing/StructuredDataDefSizeCalculator.h
index b3721cf8..be8a8283 100644
--- a/src/ObjLoading/StructuredDataDef/Parsing/StructuredDataDefSizeCalculator.h
+++ b/src/ObjLoading/StructuredDataDef/Parsing/StructuredDataDefSizeCalculator.h
@@ -16,7 +16,7 @@ namespace sdd
         explicit SizeCalculationException(std::string message);
 
         _NODISCARD const std::string& Message() const;
-        _NODISCARD char const* what() const override;
+        _NODISCARD char const* what() const noexcept override;
     };
 
     class StructuredDataDefSizeCalculator