diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f3212b8b3cb28319bb5d182ad1b8e6bb1af9cd21..26d3819c85c2dc5d92ee8319efba4f1b7f47c644 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -73,6 +73,7 @@ test-intel-bin:
     - export LD_LIBRARY_PATH=$I_MPI_ROOT/lib/:$I_MPI_ROOT/lib/release:$MKLROOT/lib/intel64:$INTEL_COMP_ROOT/lib/:$INTEL_COMP_ROOT/compiler/lib/intel64/:$LD_LIBRARY_PATH:$HOME/intel/oneapi/intelpython/latest/lib/:$HOME/intel/oneapi/intelpython/latest/lib/python3.7
     - export PYTHONPATH=$HOME/intel/oneapi/intelpython/latest/lib/python3.7/site-packages/:cpp_sisso_env/lib/python3.7/site-packages/
     - export PATH=$INTEL_COMP_ROOT/bin/:$INTEL_COMP_ROOT/bin/intel64:$I_MPI_ROOT/bin:$PATH
+    - export OMP_NUM_THREADS=1
     - cd tests/exec_test/default/
     - mpiexec -n 1 ../../../bin/sisso++
     - python ../check_model.py
@@ -140,6 +141,7 @@ test-gnu-bin:
     - source cpp_sisso_env/bin/activate
     - export LD_LIBRARY_PATH=$HOME/intel/oneapi/intelpython/latest/lib/:$HOME/intel/oneapi/intelpython/latest/lib/python3.7:$LD_LIBRARY_PATH
     - export PYTHONPATH=$HOME/intel/oneapi/intelpython/latest/lib/python3.7/site-packages/:cpp_sisso_env/lib/python3.7/site-packages/
+    - export OMP_NUM_THREADS=1
     - cd tests/exec_test/default/
     - mpiexec -n 1 ../../../bin/sisso++
     - python ../check_model.py