diff --git a/.travis.yml b/.travis.yml
index 6f6aa3a..2b3f850 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@ jobs:
       before_install:
         - choco install python --version 3.8.0
         - python -m pip install --upgrade pip
-        - python -m pip install pytest parameterize
+        - python -m pip install pytest parameterize Cython
       env: PATH=/c/Python38:/c/Python38/Scripts:$PATH
 
 before_install: