diff --git a/test-requirements.txt b/test-requirements.txt
index c4ae1e80b..cd4f37d33 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -8,6 +8,8 @@ coverage>=4.0 # Apache-2.0
 doc8 # Apache-2.0
 docker<3 # Apache-2.0
 hacking>=0.12.0,<0.13 # Apache-2.0
+# sh 1.13.1 causes molecule yamllint to fail.
+sh<1.13 # MIT
 molecule<3 # MIT
 oslotest>=1.10.0 # Apache-2.0
 # NOTE(mgoddard): This is required by tools/sphinx8.