diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0d6bf0a..2e00cf3 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -7,7 +7,7 @@ test package:
   stage: test
   script:
     - pip3 install sympy==1.1.1
-    - python setup.py develop  # build mode cache
+    - pip3 install -e .
     - py.test -r w --cov semicon --cov-report term --flakes semicon
 
 
@@ -15,7 +15,7 @@ test package with latest scipy:
   stage: test
   script:
     - pip3 install sympy==1.1.1 scipy==1.2.0rc2
-    - python setup.py develop  # build mode cache
+    - pip3 install -e .
     - py.test -r w --cov semicon --cov-report term --flakes semicon
 
 
@@ -24,13 +24,13 @@ test package with latest SymPy and Kwant stable:
   script:
     - pip3 install sympy
     - pip3 install git+https://gitlab.kwant-project.org/kwant/kwant.git@stable
-    - python setup.py develop  # build mode cache
+    - pip3 install -e .
     - py.test -r w --cov semicon --cov-report term --flakes semicon
 
 test packaging:
   stage: test
   script:
     - pip3 install sympy==1.1.1
-    - python setup.py build
-    - cd build/lib
-    - python -c 'import semicon; semicon.test()'
+    - pip3 install .
+    - cd /  # make sure we don't import the cloned version
+    - python3 -c 'import semicon; semicon.test()'