diff --git a/requirements/requirements_dev.txt b/requirements/requirements_dev.txt
index 6765971af9..d3fbaf3b6c 100644
--- a/requirements/requirements_dev.txt
+++ b/requirements/requirements_dev.txt
@@ -5,6 +5,7 @@ ipython==5.2.1
 unittest2
 pep8
 flake8
+pluggy==0.6.0
 pyflakes
 pytest==3.6.0
 pytest-cov
@@ -21,3 +22,4 @@ matplotlib
 backports.tempfile  # support in unit tests for py32+ tempfile.TemporaryDirectory
 mockldap
 sdb
+atomicwrites==1.1.5