diff --git a/Libraries/LibWeb/CSS/Properties.json b/Libraries/LibWeb/CSS/Properties.json
index 5970c1f6ff1..fe5538564a7 100644
--- a/Libraries/LibWeb/CSS/Properties.json
+++ b/Libraries/LibWeb/CSS/Properties.json
@@ -1,4 +1,7 @@
 {
+  "-moz-appearance": {
+    "legacy-alias-for": "appearance"
+  },
   "-webkit-align-content": {
     "legacy-alias-for": "align-content"
   },
diff --git a/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt b/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
index 23443bc503e..02e5bd0b4b8 100644
--- a/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
+++ b/Tests/LibWeb/Text/expected/css/CSSStyleProperties-all-supported-properties-and-default-values.txt
@@ -1,5 +1,7 @@
 All supported properties and their default values exposed from CSSStyleProperties from getComputedStyle:
 'cssFloat': 'none'
+'MozAppearance': 'none'
+'-moz-appearance': 'none'
 'WebkitAlignContent': 'normal'
 'webkitAlignContent': 'normal'
 '-webkit-align-content': 'normal'