diff --git a/requirements-dev.txt b/requirements-dev.txt
index cd02f10..2736aaa 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,4 +1,4 @@
-certifi==2019.3.9
+certifi==2019.9.11
 chardet==3.0.4
 entrypoints==0.3
 flake8==3.7.7
diff --git a/requirements.txt b/requirements.txt
index eb83bd8..ad822a0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-certifi==2019.3.9
+certifi==2019.9.11
 chardet==3.0.4
 idna==2.8
 requests==2.21.0