diff --git a/requirements.txt b/requirements.txt
index 5c7fd26..779051f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 cachetools==3.1.1
-certifi==2019.3.9
+certifi==2019.11.28
 chardet==3.0.4
 google-api-core==1.11.1
 google-auth==1.6.3