diff --git a/css/properties.json b/css/properties.json
index 533dace2..7e0e0fff 100644
--- a/css/properties.json
+++ b/css/properties.json
@@ -9574,7 +9574,7 @@
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/stroke-miterlimit"
   },
   "stroke-opacity": {
-    "syntax": "<opacity>",
+    "syntax": "<'opacity'>",
     "media": "visual",
     "inherited": true,
     "animationType": "byComputedValueType",