diff --git a/.travis.yml b/.travis.yml
index 1e5ec90..9c555cb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@ language: python
 matrix:
   include:
     - python: 3.6
-      env: NUMPY=1.18.2
+      env: NUMPY=1.18.2 CERTIFI=2020.06.20
 install: 
   - sudo apt-get install libssl-dev libcurl4-openssl-dev libyaml-dev build-essential libopenblas-dev libcap-dev ffmpeg
   - pip install -e .