diff --git a/requirements.txt b/requirements.txt
index ac22fce5..9411b08e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@
 # process, which may cause wedges in the gate later.
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
 anyjson>=0.3.3 # BSD
-eventlet!=0.18.3,>=0.18.2 # MIT
+eventlet!=0.18.3,<0.21.0,>=0.18.2 # MIT
 GitPython>=1.0.1 # BSD License (3 clause)
 kombu!=4.0.2,>=4.0.0 # BSD
 oslo.config>=3.22.0 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 91ca56e8..e35e55cc 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -11,5 +11,5 @@ oslotest>=1.10.0 # Apache-2.0
 
 # doc build requirements
 oslosphinx>=4.7.0 # Apache-2.0
-sphinx>=1.5.1 # BSD
+sphinx!=1.6.1,>=1.5.1 # BSD
 reno>=1.8.0 # Apache-2.0