diff --git a/requirements.txt b/requirements.txt
index 1466200f..ada63728 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 -e .[socks]
-pytest-xdist
+pytest-xdist==1.16.0
 pytest>=2.7
-pytest-cov
-pytest-httpbin
-pytest-mock
+pytest-cov==2.5.1
+pytest-httpbin==0.0.7
+pytest-mock==1.6.0