diff --git a/layout/style/test/property_database.js b/layout/style/test/property_database.js
index c8fc0f3448e3..b994ef9fb315 100644
--- a/layout/style/test/property_database.js
+++ b/layout/style/test/property_database.js
@@ -5256,9 +5256,8 @@ var gCSSProperties = {
     type: CSS_TYPE_LONGHAND,
     applies_to_marker: true,
     // XXX This really depends on pseudo-element-ness.
-    initial_values: ["normal"],
+    initial_values: ["normal", "none"],
     other_values: [
-      "none",
       '""',
       "''",
       '"hello"',
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index cb3ccc14e8d6..6d802be14fcf 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -7521,7 +7521,7 @@
 # Is 'content:none' supported on (non-pseudo) elements?
 - name: layout.css.element-content-none.enabled
   type: RelaxedAtomicBool
-  value: true
+  value: false
   mirror: always
   rust: true
 
diff --git a/testing/web-platform/meta/css/css-content/content-none-details.html.ini b/testing/web-platform/meta/css/css-content/content-none-details.html.ini
new file mode 100644
index 000000000000..d4a0a55af10f
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-details.html.ini
@@ -0,0 +1,2 @@
+[content-none-details.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-fieldset.html.ini b/testing/web-platform/meta/css/css-content/content-none-fieldset.html.ini
index 3eec884c0dcf..70f534034e30 100644
--- a/testing/web-platform/meta/css/css-content/content-none-fieldset.html.ini
+++ b/testing/web-platform/meta/css/css-content/content-none-fieldset.html.ini
@@ -1,3 +1,4 @@
 [content-none-fieldset.html]
+  prefs: [layout.css.element-content-none.enabled:true]
   fuzzy: # anti-aliasing color differences inside scrollbars
     maxDifference=0-4;totalPixels=0-200
diff --git a/testing/web-platform/meta/css/css-content/content-none-math.html.ini b/testing/web-platform/meta/css/css-content/content-none-math.html.ini
new file mode 100644
index 000000000000..1a3571c50750
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-math.html.ini
@@ -0,0 +1,2 @@
+[content-none-math.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-option.html.ini b/testing/web-platform/meta/css/css-content/content-none-option.html.ini
new file mode 100644
index 000000000000..37346a98fd36
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-option.html.ini
@@ -0,0 +1,2 @@
+[content-none-option.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-block.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-block.html.ini
new file mode 100644
index 000000000000..e3c9739d3697
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-block.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-block.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-columns.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-columns.html.ini
new file mode 100644
index 000000000000..970fe8b52369
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-columns.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-columns.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-flex.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-flex.html.ini
new file mode 100644
index 000000000000..38688bd9ec40
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-flex.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-flex.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-grid.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-grid.html.ini
new file mode 100644
index 000000000000..23442566bdce
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-grid.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-grid.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-ruby.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-ruby.html.ini
new file mode 100644
index 000000000000..750cef9a8698
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-ruby.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-ruby.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-root-table.html.ini b/testing/web-platform/meta/css/css-content/content-none-root-table.html.ini
new file mode 100644
index 000000000000..c215f9328313
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-root-table.html.ini
@@ -0,0 +1,2 @@
+[content-none-root-table.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-select-1.html.ini b/testing/web-platform/meta/css/css-content/content-none-select-1.html.ini
new file mode 100644
index 000000000000..8bc2a13a9ecb
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-select-1.html.ini
@@ -0,0 +1,2 @@
+[content-none-select-1.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-select-2.html.ini b/testing/web-platform/meta/css/css-content/content-none-select-2.html.ini
new file mode 100644
index 000000000000..2ddd2fbd1b9e
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-select-2.html.ini
@@ -0,0 +1,2 @@
+[content-none-select-2.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-span-dynamic.html.ini b/testing/web-platform/meta/css/css-content/content-none-span-dynamic.html.ini
new file mode 100644
index 000000000000..34b67318231e
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-span-dynamic.html.ini
@@ -0,0 +1,2 @@
+[content-none-span-dynamic.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-span.html.ini b/testing/web-platform/meta/css/css-content/content-none-span.html.ini
new file mode 100644
index 000000000000..e3e7dbb4d428
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-span.html.ini
@@ -0,0 +1,2 @@
+[content-none-span.html]
+  prefs: [layout.css.element-content-none.enabled:true]
diff --git a/testing/web-platform/meta/css/css-content/content-none-table.html.ini b/testing/web-platform/meta/css/css-content/content-none-table.html.ini
new file mode 100644
index 000000000000..15e335f88c96
--- /dev/null
+++ b/testing/web-platform/meta/css/css-content/content-none-table.html.ini
@@ -0,0 +1,2 @@
+[content-none-table.html]
+  prefs: [layout.css.element-content-none.enabled:true]