diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f67b3af19e9455d9267bdad4ba453d6a6383253c..65d26bbea656a249aa9d742327b45cc4eea0c437 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -39,7 +39,9 @@ verify_tag:
 pages:
   stage: deploy
   script:
-    - pip install sphinx sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder numpy sphinx_rtd_theme
+    - conda install -c conda-forge sphinx
+    - conda install -c conda-forge numpy
+    - pip install sphinxcontrib-blockdiag blockdiag sphinxcontrib-restbuilder sphinx_rtd_theme
     - pip install git+https://github.com/crossnox/m2r
     - python setup.py install
     - sphinx-build -b html -d public/doctrees   doc public