diff --git a/setup.cfg b/setup.cfg
index d91f4399..a4f5060c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -18,7 +18,7 @@ classifiers =
 [options]
 packages = find:
 install_requires =
-    ruamel.yaml>=0.15
+    ruamel.yaml>=0.15,<0.19
     tomli>=1.1.0;python_version<"3.11"
 python_requires = >=3.10