diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index c7aea5b84d8..f5113de277d 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1588,23 +1588,9 @@ impl<'le> TElement for GeckoElement<'le> {
         use crate::properties::longhands::_x_lang::SpecifiedValue as SpecifiedLang;
         use crate::properties::longhands::_x_text_zoom::SpecifiedValue as SpecifiedZoom;
         use crate::properties::longhands::color::SpecifiedValue as SpecifiedColor;
-        use crate::properties::longhands::text_align::SpecifiedValue as SpecifiedTextAlign;
         use crate::stylesheets::layer_rule::LayerOrder;
         use crate::values::specified::color::Color;
         lazy_static! {
-            static ref TH_RULE: ApplicableDeclarationBlock = {
-                let global_style_data = &*GLOBAL_STYLE_DATA;
-                let pdb = PropertyDeclarationBlock::with_one(
-                    PropertyDeclaration::TextAlign(SpecifiedTextAlign::MozCenterOrInherit),
-                    Importance::Normal,
-                );
-                let arc = Arc::new_leaked(global_style_data.shared_lock.wrap(pdb));
-                ApplicableDeclarationBlock::from_declarations(
-                    arc,
-                    ServoCascadeLevel::PresHints,
-                    LayerOrder::root(),
-                )
-            };
             static ref TABLE_COLOR_RULE: ApplicableDeclarationBlock = {
                 let global_style_data = &*GLOBAL_STYLE_DATA;
                 let pdb = PropertyDeclarationBlock::with_one(
@@ -1649,9 +1635,7 @@ impl<'le> TElement for GeckoElement<'le> {
         let ns = self.namespace_id();
         // <th> elements get a default MozCenterOrInherit which may get overridden
         if ns == structs::kNameSpaceID_XHTML as i32 {
-            if self.local_name().as_ptr() == atom!("th").as_ptr() {
-                hints.push(TH_RULE.clone());
-            } else if self.local_name().as_ptr() == atom!("table").as_ptr() &&
+            if self.local_name().as_ptr() == atom!("table").as_ptr() &&
                 self.as_node().owner_doc().quirks_mode() == QuirksMode::Quirks
             {
                 hints.push(TABLE_COLOR_RULE.clone());
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index b5ad73bf250..9c58b6a4572 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -528,11 +528,20 @@ pub enum TextAlign {
     /// unlike other keywords.
     #[cfg(feature = "gecko")]
     MatchParent,
-    /// `MozCenterOrInherit` value of text-align property. It cannot be parsed,
-    /// only set directly on the elements and it has a different handling
-    /// unlike other values.
+    /// This is how we implement the following HTML behavior from
+    /// https://html.spec.whatwg.org/#tables-2:
+    ///
+    ///     User agents are expected to have a rule in their user agent style sheet
+    ///     that matches th elements that have a parent node whose computed value
+    ///     for the 'text-align' property is its initial value, whose declaration
+    ///     block consists of just a single declaration that sets the 'text-align'
+    ///     property to the value 'center'.
+    ///
+    /// Since selectors can't depend on the ancestor styles, we implement it with a
+    /// magic value that computes to the right thing. Since this is an
+    /// implementation detail, it shouldn't be exposed to web content.
     #[cfg(feature = "gecko")]
-    #[css(skip)]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozCenterOrInherit,
 }