diff --git a/css/properties/writing-mode.json b/css/properties/writing-mode.json
index c72dd0be0708ef..bd16328421f6b3 100644
--- a/css/properties/writing-mode.json
+++ b/css/properties/writing-mode.json
@@ -79,7 +79,7 @@
                 "version_added": "48"
               },
               "chrome_android": "mirror",
-              "edge": "mirror",
+              "edge": "12",
               "firefox": {
                 "version_added": "43"
               },
@@ -442,7 +442,7 @@
                 "version_added": "48"
               },
               "chrome_android": "mirror",
-              "edge": "mirror",
+              "edge": "12",
               "firefox": {
                 "version_added": "43"
               },
@@ -475,7 +475,7 @@
                 "version_added": "48"
               },
               "chrome_android": "mirror",
-              "edge": "mirror",
+              "edge": "12",
               "firefox": {
                 "version_added": "43"
               },