diff --git a/requirements/rtd.txt b/requirements/rtd.txt
index cf39d6da..0b160d74 100644
--- a/requirements/rtd.txt
+++ b/requirements/rtd.txt
@@ -14,7 +14,7 @@ pyspf==2.0.14 # rq.filter: ==2.0.12t
 spoon==1.0.6
 dnspython3==1.12.0
 py3dns==3.1.0
-mock==2.0.0
+mock==5.1.0
 pytest==2.9.1
 pytest-cov==2.2.1
 python-coveralls==2.7.0
diff --git a/requirements/tests.txt b/requirements/tests.txt
index d7a947b4..2ab3bc2c 100644
--- a/requirements/tests.txt
+++ b/requirements/tests.txt
@@ -1,5 +1,5 @@
 # Requirements for running tests.
-mock==2.0.0
+mock==5.1.0
 pytest==2.9.1
 pytest-cov==2.2.1
 python-coveralls==2.7.0