diff --git a/css/functions.json b/css/functions.json
index 760a2130..9129b4c3 100644
--- a/css/functions.json
+++ b/css/functions.json
@@ -15,6 +15,14 @@
     "status": "standard",
     "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/acos"
   },
+  "alpha()": {
+    "syntax": "alpha(from <<color>> / [<<alpha-value>> | none])",
+    "groups": [
+      "CSS Color"
+    ],
+    "status": "standard",
+    "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/color_value/alpha"
+  },
   "anchor()": {
     "syntax": "anchor( <anchor-name>? && <anchor-side>, <length-percentage>? )",
     "groups": [