diff --git a/components/style/gecko/pseudo_element_definition.mako.rs b/components/style/gecko/pseudo_element_definition.mako.rs
index b507fafd865..be0318eadea 100644
--- a/components/style/gecko/pseudo_element_definition.mako.rs
+++ b/components/style/gecko/pseudo_element_definition.mako.rs
@@ -8,9 +8,9 @@ pub enum PseudoElement {
     % for pseudo in PSEUDOS:
         /// ${pseudo.value}
         % if pseudo.is_tree_pseudo_element():
-        ${pseudo.capitalized()}(ThinBoxedSlice<Atom>),
+        ${pseudo.capitalized_pseudo()}(ThinBoxedSlice<Atom>),
         % else:
-        ${pseudo.capitalized()},
+        ${pseudo.capitalized_pseudo()},
         % endif
     % endfor
 }
@@ -41,7 +41,7 @@ pub const EAGER_PSEUDOS: [PseudoElement; EAGER_PSEUDO_COUNT] = [
 ];
 
 <%def name="pseudo_element_variant(pseudo, tree_arg='..')">\
-PseudoElement::${pseudo.capitalized()}${"({})".format(tree_arg) if pseudo.is_tree_pseudo_element() else ""}\
+PseudoElement::${pseudo.capitalized_pseudo()}${"({})".format(tree_arg) if pseudo.is_tree_pseudo_element() else ""}\
 </%def>
 
 impl PseudoElement {
@@ -120,7 +120,7 @@ impl PseudoElement {
                 % elif pseudo.is_anon_box():
                     structs::CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS,
                 % else:
-                    structs::SERVO_CSS_PSEUDO_ELEMENT_FLAGS_${pseudo.original_ident},
+                    structs::SERVO_CSS_PSEUDO_ELEMENT_FLAGS_${pseudo.pseudo_ident},
                 % endif
             % endfor
         }
@@ -132,7 +132,7 @@ impl PseudoElement {
         match type_ {
             % for pseudo in PSEUDOS:
                 % if not pseudo.is_anon_box():
-                    CSSPseudoElementType::${pseudo.original_ident} => {
+                    CSSPseudoElementType::${pseudo.pseudo_ident} => {
                         Some(${pseudo_element_variant(pseudo)})
                     },
                 % endif
@@ -149,13 +149,13 @@ impl PseudoElement {
         match *self {
             % for pseudo in PSEUDOS:
                 % if not pseudo.is_anon_box():
-                    PseudoElement::${pseudo.capitalized()} => CSSPseudoElementType::${pseudo.original_ident},
+                    PseudoElement::${pseudo.capitalized_pseudo()} => CSSPseudoElementType::${pseudo.pseudo_ident},
                 % elif pseudo.is_tree_pseudo_element():
-                    PseudoElement::${pseudo.capitalized()}(..) => CSSPseudoElementType::XULTree,
+                    PseudoElement::${pseudo.capitalized_pseudo()}(..) => CSSPseudoElementType::XULTree,
                 % elif pseudo.is_inheriting_anon_box():
-                    PseudoElement::${pseudo.capitalized()} => CSSPseudoElementType_InheritingAnonBox,
+                    PseudoElement::${pseudo.capitalized_pseudo()} => CSSPseudoElementType_InheritingAnonBox,
                 % else:
-                    PseudoElement::${pseudo.capitalized()} => CSSPseudoElementType::NonInheritingAnonBox,
+                    PseudoElement::${pseudo.capitalized_pseudo()} => CSSPseudoElementType::NonInheritingAnonBox,
                 % endif
             % endfor
         }
@@ -171,7 +171,7 @@ impl PseudoElement {
     pub fn tree_pseudo_args(&self) -> Option<<&[Atom]> {
         match *self {
             % for pseudo in TREE_PSEUDOS:
-            PseudoElement::${pseudo.capitalized()}(ref args) => Some(args),
+            PseudoElement::${pseudo.capitalized_pseudo()}(ref args) => Some(args),
             % endfor
             _ => None,
         }
@@ -213,7 +213,7 @@ impl PseudoElement {
         % for pseudo in PSEUDOS:
             % if pseudo.is_tree_pseudo_element():
                 if atom == &atom!("${pseudo.value}") {
-                    return Some(PseudoElement::${pseudo.capitalized()}(args.into()));
+                    return Some(PseudoElement::${pseudo.capitalized_pseudo()}(args.into()));
                 }
             % endif
         % endfor
diff --git a/components/style/gecko/regen_atoms.py b/components/style/gecko/regen_atoms.py
index 6d812a4cf50..f4e87c32f8d 100755
--- a/components/style/gecko/regen_atoms.py
+++ b/components/style/gecko/regen_atoms.py
@@ -28,14 +28,14 @@ def gnu_symbolify(source, ident):
     return "_ZN{}{}{}{}E".format(len(source.CLASS), source.CLASS, len(ident), ident)
 
 
-def msvc64_symbolify(source, ident):
-    return "?{}@{}@@2PEAV{}@@EA".format(ident, source.CLASS, source.TYPE)
+def msvc64_symbolify(source, ident, ty):
+    return "?{}@{}@@2PEAV{}@@EA".format(ident, source.CLASS, ty)
 
 
-def msvc32_symbolify(source, ident):
+def msvc32_symbolify(source, ident, ty):
     # Prepend "\x01" to avoid LLVM prefixing the mangled name with "_".
     # See https://github.com/rust-lang/rust/issues/36097
-    return "\\x01?{}@{}@@2PAV{}@@A".format(ident, source.CLASS, source.TYPE)
+    return "\\x01?{}@{}@@2PAV{}@@A".format(ident, source.CLASS, ty)
 
 
 class GkAtomSource:
@@ -46,16 +46,6 @@ class GkAtomSource:
     TYPE = "nsStaticAtom"
 
 
-class CSSPseudoElementsAtomSource:
-    PATTERN = re.compile('^(CSS_PSEUDO_ELEMENT)\(([^,]*),[^"]*"([^"]*)",()',
-                         re.MULTILINE)
-    FILE = "include/nsCSSPseudoElementList.h"
-    CLASS = "nsCSSPseudoElements"
-    # NB: nsICSSPseudoElement is effectively the same as a nsStaticAtom, but we need
-    # this for MSVC name mangling.
-    TYPE = "nsICSSPseudoElement"
-
-
 class CSSAnonBoxesAtomSource:
     PATTERN = re.compile('^(CSS_ANON_BOX|CSS_NON_INHERITING_ANON_BOX|CSS_WRAPPER_ANON_BOX)\(([^,]*),[^"]*"([^"]*)"()\)',  # NOQA: E501
                          re.MULTILINE)
@@ -66,7 +56,6 @@ class CSSAnonBoxesAtomSource:
 
 SOURCES = [
     GkAtomSource,
-    CSSPseudoElementsAtomSource,
     CSSAnonBoxesAtomSource,
 ]
 
@@ -86,6 +75,11 @@ class Atom:
         self.source = source
         self.macro = macro_name
         self.ty = ty
+        if self.is_pseudo():
+            if self.is_non_anon_box_pseudo():
+                self.pseudo_ident = (ident.split("_", 1))[1]
+            else:
+                self.pseudo_ident = ident
         if self.is_anon_box():
             assert self.is_inheriting_anon_box() or self.is_non_inheriting_anon_box()
 
@@ -96,16 +90,22 @@ class Atom:
         return gnu_symbolify(self.source, self.original_ident)
 
     def msvc32_symbol(self):
-        return msvc32_symbolify(self.source, self.original_ident)
+        return msvc32_symbolify(self.source, self.original_ident, self.ty)
 
     def msvc64_symbol(self):
-        return msvc64_symbolify(self.source, self.original_ident)
+        return msvc64_symbolify(self.source, self.original_ident, self.ty)
 
     def type(self):
         return self.ty
 
-    def capitalized(self):
-        return self.original_ident[0].upper() + self.original_ident[1:]
+    def capitalized_pseudo(self):
+        return self.pseudo_ident[0].upper() + self.pseudo_ident[1:]
+
+    def is_pseudo(self):
+        return self.is_non_anon_box_pseudo() or self.is_anon_box()
+
+    def is_non_anon_box_pseudo(self):
+        return self.type() == "nsICSSPseudoElement"
 
     def is_anon_box(self):
         return self.type() == "nsICSSAnonBoxPseudo"