diff --git a/layout/mathml/mathml.css b/layout/mathml/mathml.css
index d958b726125c..e1dbc487ace9 100644
--- a/layout/mathml/mathml.css
+++ b/layout/mathml/mathml.css
@@ -45,25 +45,6 @@ math[display="inline" i] {
math-style: compact;
}
-/**************************************************************************/
-/* Token elements */
-/**************************************************************************/
-
-@media not (-moz-mathml-core-ms) {
- ms {
- display: inline;
- }
- ms:before, ms:after {
- content: "\0022"
- }
- ms[lquote]:before {
- content: attr(lquote)
- }
- ms[rquote]:after {
- content: attr(rquote)
- }
-}
-
/**************************************************************************/
/* Links */
/**************************************************************************/
diff --git a/layout/reftests/mathml/quotes-1-ref.xhtml b/layout/reftests/mathml/quotes-1-ref.xhtml
deleted file mode 100644
index ff3ac0e4ffbc..000000000000
--- a/layout/reftests/mathml/quotes-1-ref.xhtml
+++ /dev/null
@@ -1,18 +0,0 @@
-
-
-
-
-
-:L_R
-:L_"
-:"_R
-:L_"
-:"_R
-:"_"
-:"_"
-:"_"
-
-
diff --git a/layout/reftests/mathml/quotes-1.xhtml b/layout/reftests/mathml/quotes-1.xhtml
deleted file mode 100644
index e833966f8ac0..000000000000
--- a/layout/reftests/mathml/quotes-1.xhtml
+++ /dev/null
@@ -1,39 +0,0 @@
-
-
-
-
-
-:_
-:_
-:_
-:_
-:_
-:_
-:_
-:_
-
-
-
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index cbfedd790a9f..4a227e4e4a71 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -9395,13 +9395,6 @@
mirror: always
rust: true
-# Whether to disable the lquote/rquote attributes of the element.
-- name: mathml.ms_lquote_rquote_attributes.disabled
- type: bool
- value: true
- mirror: always
- rust: true
-
# Whether to disable legacy names "thickmathspace", "mediummathspace",
# "thickmathspace" etc for length attributes.
- name: mathml.mathspace_names.disabled
diff --git a/servo/components/style/gecko/media_features.rs b/servo/components/style/gecko/media_features.rs
index b0154d812e65..afd24adb59f4 100644
--- a/servo/components/style/gecko/media_features.rs
+++ b/servo/components/style/gecko/media_features.rs
@@ -684,7 +684,7 @@ macro_rules! bool_pref_feature {
/// to support new types in these entries and (2) ensuring that either
/// nsPresContext::MediaFeatureValuesChanged is called when the value that
/// would be returned by the evaluator function could change.
-pub static MEDIA_FEATURES: [QueryFeatureDescription; 62] = [
+pub static MEDIA_FEATURES: [QueryFeatureDescription; 61] = [
feature!(
atom!("width"),
AllowsRanges::Yes,
@@ -997,11 +997,6 @@ pub static MEDIA_FEATURES: [QueryFeatureDescription; 62] = [
atom!("-moz-mathml-core-maction-and-semantics"),
"mathml.legacy_maction_and_semantics_implementations.disabled"
),
- // media query for MathML Core's implementation of ms
- bool_pref_feature!(
- atom!("-moz-mathml-core-ms"),
- "mathml.ms_lquote_rquote_attributes.disabled"
- ),
// media query for popover attribute
bool_pref_feature!(atom!("-moz-popover-enabled"), "dom.element.popover.enabled"),
// media query for MathML Core's implementation of mi
diff --git a/widget/nsXPLookAndFeel.cpp b/widget/nsXPLookAndFeel.cpp
index 3c15f47046c8..2c58c4902064 100644
--- a/widget/nsXPLookAndFeel.cpp
+++ b/widget/nsXPLookAndFeel.cpp
@@ -505,7 +505,6 @@ static constexpr struct {
{"browser.theme.toolbar-theme"_ns, widget::ThemeChangeKind::AllBits},
{"browser.theme.content-theme"_ns},
{"mathml.legacy_maction_and_semantics_implementations.disabled"_ns},
- {"mathml.ms_lquote_rquote_attributes.disabled"_ns},
{"dom.element.popover.enabled"_ns},
{"mathml.legacy_mathvariant_attribute.disabled"_ns},
};
diff --git a/xpcom/ds/StaticAtoms.py b/xpcom/ds/StaticAtoms.py
index bf0ca61b3ffd..2fbb11fd7b34 100644
--- a/xpcom/ds/StaticAtoms.py
+++ b/xpcom/ds/StaticAtoms.py
@@ -2395,8 +2395,6 @@ STATIC_ATOMS = [
Atom("onsupportedkeyschange", "onsupportedkeyschange"),
# media query for MathML Core's implementation of maction/semantics
Atom("_moz_mathml_core_maction_and_semantics", "-moz-mathml-core-maction-and-semantics"),
- # media query for MathML Core's implementation of ms
- Atom("_moz_mathml_core_ms", "-moz-mathml-core-ms"),
Atom("_moz_popover_enabled", "-moz-popover-enabled"),
# media query for MathML Core's implementation of mi
Atom("_moz_mathml_core_mi", "-moz-mathml-core-mi"),