diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ce7460b9a49f3f7ca54563980a69a9b7455aef72..bcc8c4331d2e8ee7b1816e4557feb5dad480a1bd 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,8 +6,8 @@ tests:
     script:
         - cd python
         - pip3 install --no-deps ltfatpy madarrays yafe skpomade pandas
-        - pip3 install scipy=1.4.1 -U
-        - pip3 install matplotlib=3.1.2 -U
+        - pip3 install 'scipy==1.4.1' -U
+        - pip3 install 'matplotlib==3.1.2' -U
         - pip3 install --no-deps .
         - python3 tffpy/tests/ci_config.py
         - pytest-3
@@ -22,8 +22,8 @@ pages:
     script:
         - cd python
         - pip3 install --no-deps ltfatpy madarrays yafe skpomade pandas
-        - pip3 install scipy=1.4.1 -U
-        - pip3 install matplotlib=3.1.2 -U
+        - pip3 install 'scipy==1.4.1' -U
+        - pip3 install 'matplotlib==3.1.2' -U
         - pip3 install --no-deps .
         - python3 setup.py build_sphinx
         - python3 tffpy/tests/ci_config.py