diff --git a/Geant4/G4config/CMakeLists.txt b/Geant4/G4config/CMakeLists.txt
index c0d35d43c318178b31fd34a7c3559cea67f019c9..6e61026fb7d97f98eeff3cf95a8c981f477cbc8b 100644
--- a/Geant4/G4config/CMakeLists.txt
+++ b/Geant4/G4config/CMakeLists.txt
@@ -51,7 +51,7 @@ ExternalProject_Add(Geant4
    GIT_REPOSITORY ${GEANT4_SRCS_REPOSITORY}
    GIT_TAG ${GEANT4_TAG}
    CMAKE_ARGS -DCMAKE_TOOLCHAIN_FILE=${CMAKE_SOURCE_DIR}/toolchain.cmake
-              -DGEANT4_BUILD_CXXSTD=${GAUDI_CXX_STANDARD}
+              -DGEANT4_BUILD_CXXSTD=${CXX_STANDARD}
               -DGEANT4_INSTALL_DATA=OFF
               -DGEANT4_USE_SYSTEM_CLHEP=ON
               -DGEANT4_USE_XM=ON