diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c8edc1672420188eba9ab1dc7bd490897792d8e2..ed9b53cdf57ef9de786020da9a7e76da140ba2bc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,7 +10,7 @@ slc6-gcc48:
     - source .gitlab-ci.d/init_x86_64-slc6-gcc48-opt.sh
     - mkdir build 
     - cd build
-    - cmake -D DD4HEP_USE_GEANT4=ON -D DD4HEP_USE_BOOST=ON -DBoost_NO_BOOST_CMAKE=ON -D DD4HEP_USE_LCIO=ON -D BUILD_TESTING=ON -DCLHEP_DIR=$CLHEP -D Geant4_DIR=$G4INSTALL/lib64/Geant4-10.1.2 ..
+    - cmake -D DD4HEP_USE_GEANT4=ON -D DD4HEP_USE_BOOST=ON -DBoost_NO_BOOST_CMAKE=ON -D DD4HEP_USE_LCIO=ON -D BUILD_TESTING=ON -DCLHEP_DIR=$CLHEP -D Geant4_DIR=$G4INSTALL/lib64/Geant4-10.1.2 -D DD4HEP_USE_CXX11=ON ..
     - make -j2
     - make install
 
@@ -23,6 +23,6 @@ slc6-gcc49:
     - source .gitlab-ci.d/init_x86_64-slc6-gcc49-opt.sh
     - mkdir build 
     - cd build
-    - cmake -D DD4HEP_USE_GEANT4=ON -D DD4HEP_USE_BOOST=ON -DBoost_NO_BOOST_CMAKE=ON -D DD4HEP_USE_LCIO=ON -D BUILD_TESTING=ON -DCLHEP_DIR=$CLHEP -D Geant4_DIR=$G4INSTALL/lib64/Geant4-10.1.2 ..
+    - cmake -D DD4HEP_USE_GEANT4=ON -D DD4HEP_USE_BOOST=ON -DBoost_NO_BOOST_CMAKE=ON -D DD4HEP_USE_LCIO=ON -D BUILD_TESTING=ON -DCLHEP_DIR=$CLHEP -D Geant4_DIR=$G4INSTALL/lib64/Geant4-10.1.2 -D DD4HEP_USE_CXX14=ON ..
     - make -j2
     - make install