diff --git a/requirements-dev.txt b/requirements-dev.txt
index ea4c0a3..88b4f2a 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -2,7 +2,7 @@
 flake8==3.5.0
 pytest==3.5.1
 pytest-cov==2.5.1
-pytest-mock==1.6.3
+pytest-mock==1.9.0
 coverage==4.5.1
 sphinx==1.7.3
 pep257==0.7.0