diff --git a/components/style/properties/counted_unknown_properties.py b/components/style/properties/counted_unknown_properties.py
index 2548e591060..6a562a9abab 100644
--- a/components/style/properties/counted_unknown_properties.py
+++ b/components/style/properties/counted_unknown_properties.py
@@ -121,4 +121,5 @@ COUNTED_UNKNOWN_PROPERTIES = [
     "-webkit-columns",
     "-webkit-column-rule-color",
     "-webkit-shape-margin",
+    "content-visibility",
 ]