diff --git a/requirements.txt b/requirements.txt
index 53cd313c..0839778e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 botocore>=1.5.1 # Apache-2.0
-setuptools!=24.0.0,!=34.0.0,!=34.0.1,!=34.0.2,!=34.0.3,!=34.1.0,!=34.1.1,!=34.2.0,!=34.3.0,!=34.3.1,!=34.3.2,!=36.2.0,>=16.0 # PSF/ZPL
+setuptools!=24.0.0,!=34.0.0,!=34.0.1,!=34.0.2,!=34.0.3,!=34.1.0,!=34.1.1,!=34.2.0,!=34.3.0,!=34.3.1,!=34.3.2,!=36.2.0,>=21.0.0 # PSF/ZPL
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 python-swiftclient>=3.2.0 # Apache-2.0
 python-cinderclient>=3.3.0 # Apache-2.0