diff --git a/dev-requirements.txt b/dev-requirements.txt
index 787a5c5..ed38b0e 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -2,4 +2,4 @@ pytest>=2.5
 sphinx>=1.1
 colour>=0.0.5
 mock>=1.0
-pep8>=1.5
+pep8>=1.5.7