diff --git a/.travis.yml b/.travis.yml
index 2c065d415..7c5c42803 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,6 +16,7 @@ python:
   - "3.5"
 install:
     - wget -O glfw-3.2.1.zip https://github.com/glfw/glfw/archive/3.2.1.zip
+    - pip install flake8
     - unzip glfw-3.2.1.zip
     - cd glfw-3.2.1
     - cmake -DBUILD_SHARED_LIBS=ON -DGLFW_BUILD_EXAMPLES=OFF -DGLFW_BUILD_TESTS=OFF -DGLFW_BUILD_DOCS=OFF -DCMAKE_INSTALL_PREFIX=$HOME/glfw