diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index a9290a98aad7800329d5bf2ada49e0ce24ed310b..b78507de0abd0fb9b33b37b8e7a0b0d61311d372 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,7 +20,7 @@ before_script:
   - apt-get update -yq && apt-get -o dir::cache::archives="$APT_CACHE_DIR" install -y cmake libfftw3-dev
   - apt-get -o dir::cache::archives="$APT_CACHE_DIR" install -y liblapack-dev python3.5 python3.5-dev python3-pip
   - pip3 install --upgrade pip
-  - pip3 install scipy matplotlib nose coverage
+  - pip3 install scipy matplotlib nose coverage cython
 
 # Main build 
 build: