diff --git a/requirements_dev.txt b/requirements_dev.txt
index 182b536..0ff72cb 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -2,12 +2,12 @@ pip==9.0.1
 bumpversion==0.5.3
 wheel==0.30.0
 watchdog==0.8.3
-flake8==3.5.-
+flake8==3.5.0
 tox==2.9.1
 coverage==4.4.2
 Sphinx==1.6.5
-cryptography==2.1.3
+cryptography==2.1.4
 PyYAML==3.12
-pytest==3.2.5
+pytest==3.3.1
 pytest-runner==3.0
 vcrpy==1.11.1