diff --git a/.travis.yml b/.travis.yml
index 8efd208..529d759 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@ python:
 # command to install dependencies
 
 install: 
-  - "pip install -r requirements.txt"     
+  - "pip install --upgrade -r requirements.txt"     
   - "pip install -e ."
 
 # command to run tests