diff --git a/r2/r2/lib/cssfilter.py b/r2/r2/lib/cssfilter.py
index c2802445d..941495223 100644
--- a/r2/r2/lib/cssfilter.py
+++ b/r2/r2/lib/cssfilter.py
@@ -265,6 +265,7 @@ SAFE_FUNCTIONS = {
     "attr",
     "calc",
     "counter",
+    "counters",
     "hsl",
     "hsla",
     "lang",