diff --git a/.travis.yml b/.travis.yml
index e9e19d691..a18c6e5a4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -39,6 +39,7 @@ matrix:
                 - clang
 
 install:
+    - if [[ "$RUN_FLAKE" == "1" ]]; then pip install flake8; fi
     - pip install flake8
     - wget -O glfw-3.2.1.zip https://github.com/glfw/glfw/archive/3.2.1.zip
     - unzip glfw-3.2.1.zip