diff --git a/Database/AthenaRoot/RootAuxDynIO/src/RootAuxDynIO.cxx b/Database/AthenaRoot/RootAuxDynIO/src/RootAuxDynIO.cxx
index da785e332bf1b517cb590983561934407072f54b..852bb18eb098976440ef8180b4d50d876d1beaca 100644
--- a/Database/AthenaRoot/RootAuxDynIO/src/RootAuxDynIO.cxx
+++ b/Database/AthenaRoot/RootAuxDynIO/src/RootAuxDynIO.cxx
@@ -29,7 +29,9 @@ namespace RootAuxDynIO
    hasAuxStore(std::string_view fieldname, TClass *tc) {
       // check the name first, and only if it does not match AUX_POSTFIX ask TClass
       return endsWithAuxPostfix(fieldname)
-         or ( tc and tc->GetBaseClass("SG::IAuxStore") );
+         or ( tc and ( tc->GetBaseClass("SG::IAuxStore")
+                       // the IAuxStore property is used in DataModelTests
+                       or RootType(tc).Properties().HasProperty("IAuxStore") ));
    }