diff --git a/requirements.txt b/requirements.txt
index f23b724489..49d67828bf 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ intelhex>=1.3,<=2.2.1
 junit-xml==1.8
 pyYAML==3.13
 urllib3[secure]==1.23
-requests==2.19.1
+requests>=2.20,<2.21
 mbed-ls>=1.5.1,<1.7
 mbed-host-tests>=1.1.2,<=1.5
 mbed-greentea>=0.2.24,<=1.5