diff --git a/dev-requirements.txt b/dev-requirements.txt
index 97ca69b54..2492eddac 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,8 +1,8 @@
 # This file lists the dependencies of this extension.
-# Install with a command like: pip install -r requirements.txt 
+# Install with a command like: pip install -r requirements.txt
 flake8==2.1.0
 testfixtures==4.10.0
-fs==0.5.4
+fs
 mock==2.0.0
 pylons==0.9.7
 nose==1.3.7