diff --git a/testing/mozharness/requirements.txt b/testing/mozharness/requirements.txt
index 632355c542..9e82a41931 100644
--- a/testing/mozharness/requirements.txt
+++ b/testing/mozharness/requirements.txt
@@ -20,6 +20,6 @@ simplejson==2.1.1
 unittest2==0.5.1
 virtualenv==1.5.1
 wsgiref==0.1.2
-urllib3==1.9.1
+urllib3==1.26.5
 google-api-python-client==1.5.1
 oauth2client==1.4.2