diff --git a/requirements.txt b/requirements.txt
index b7ca3196..08c27a57 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-ansible-core>=2.12 # require undef filter
+ansible-core>=2.12,<2.19 # require undef filter
 azimuth-robotframework
 bcrypt==4.0.1  # this is the latest version that doesn't emit a warning
 jmespath