diff --git a/lower-constraints.txt b/lower-constraints.txt
index 47f5027e21..e6c3c91731 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -1,5 +1,6 @@
 alabaster==0.7.10
 asn1crypto==0.24.0
+attrs==21.4.0
 Babel==2.5.3
 bandit==1.1.0
 boto==2.32.1