diff --git a/components/style/gecko/regen_atoms.py b/components/style/gecko/regen_atoms.py
index 0066d06d054..cf7cc77c16f 100755
--- a/components/style/gecko/regen_atoms.py
+++ b/components/style/gecko/regen_atoms.py
@@ -132,7 +132,7 @@ PRELUDE = '''
 RULE_TEMPLATE = '''
     ("{atom}") => {{{{
         #[allow(unsafe_code)] #[allow(unused_unsafe)]
-        unsafe {{ $crate::string_cache::Atom::from_index({index}) }}
+        unsafe {{ $crate::string_cache::Atom::from_index_unchecked({index}) }}
     }}}};
 '''[1:]
 
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index 5d849a96f6e..e1da47e937e 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -49,10 +49,15 @@ macro_rules! local_name {
     };
 }
 
-/// A handle to a Gecko atom.
+/// A handle to a Gecko atom. This is a type that can represent either:
+///
+///  * A strong reference to a dynamic atom (an `nsAtom` pointer), in which case
+///    the `usize` just holds the pointer value.
+///
+///  * A byte offset from `gGkAtoms` to the `nsStaticAtom` object (shifted to
+///    the left one bit, and with the lower bit set to `1` to differentiate it
+///    from the above), so `(offset << 1 | 1)`.
 ///
-/// This is either a strong reference to a dynamic atom (an nsAtom pointer),
-/// or an offset from gGkAtoms to the nsStaticAtom object.
 #[derive(Eq, PartialEq)]
 #[repr(C)]
 pub struct Atom(NonZeroUsize);
@@ -87,7 +92,7 @@ fn static_atoms() -> &'static [nsStaticAtom; STATIC_ATOM_COUNT] {
 fn valid_static_atom_addr(addr: usize) -> bool {
     unsafe {
         let atoms = static_atoms();
-        let start = atoms.get_unchecked(0) as *const _;
+        let start = atoms.as_ptr();
         let end = atoms.get_unchecked(STATIC_ATOM_COUNT) as *const _;
         let in_range = addr >= start as usize && addr < end as usize;
         let aligned = addr % mem::align_of::<nsStaticAtom>() == 0;
@@ -379,17 +384,16 @@ impl Atom {
     }
 
     /// Creates a static atom from its index in the static atom table, without
-    /// checking in release builds.
+    /// checking.
     #[inline]
-    pub unsafe fn from_index(index: u16) -> Self {
-        let ptr = static_atoms().get_unchecked(index as usize) as *const _;
-        let handle = make_static_handle(ptr);
-        let atom = Atom(handle);
-        debug_assert!(valid_static_atom_addr(ptr as usize));
-        debug_assert!(atom.is_static());
-        debug_assert!((*atom).is_static());
-        debug_assert!(handle == make_handle(atom.as_ptr()));
-        atom
+    pub const unsafe fn from_index_unchecked(index: u16) -> Self {
+        // FIXME(emilio): No support for debug_assert! in const fn for now. Note
+        // that violating this invariant will debug-assert in the `Deref` impl
+        // though.
+        //
+        // debug_assert!((index as usize) < STATIC_ATOM_COUNT);
+        let offset = (index as usize) * std::mem::size_of::<nsStaticAtom>() + kGkAtomsArrayOffset as usize;
+        Atom(NonZeroUsize::new_unchecked((offset << 1) | 1))
     }
 
     /// Creates an atom from an atom pointer.
diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index ac528f4fb37..6a3dc75f4d8 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -63,43 +63,38 @@ where
 {
     use crate::Atom;
 
-    // FIXME(emilio): This should be an actual static.
-    lazy_static! {
-        static ref SPECIAL_HTML_ELEMENTS: [Atom; 16] = [
-            atom!("br"),
-            atom!("wbr"),
-            atom!("meter"),
-            atom!("progress"),
-            atom!("canvas"),
-            atom!("embed"),
-            atom!("object"),
-            atom!("audio"),
-            atom!("iframe"),
-            atom!("img"),
-            atom!("video"),
-            atom!("frame"),
-            atom!("frameset"),
-            atom!("input"),
-            atom!("textarea"),
-            atom!("select"),
-        ];
-    }
+    const SPECIAL_HTML_ELEMENTS: [Atom; 16] = [
+        atom!("br"),
+        atom!("wbr"),
+        atom!("meter"),
+        atom!("progress"),
+        atom!("canvas"),
+        atom!("embed"),
+        atom!("object"),
+        atom!("audio"),
+        atom!("iframe"),
+        atom!("img"),
+        atom!("video"),
+        atom!("frame"),
+        atom!("frameset"),
+        atom!("input"),
+        atom!("textarea"),
+        atom!("select"),
+    ];
 
     // https://drafts.csswg.org/css-display/#unbox-svg
     //
     // There's a note about "Unknown elements", but there's not a good way to
     // know what that means, or to get that information from here, and no other
     // UA implements this either.
-    lazy_static! {
-        static ref SPECIAL_SVG_ELEMENTS: [Atom; 6] = [
-            atom!("svg"),
-            atom!("a"),
-            atom!("g"),
-            atom!("use"),
-            atom!("tspan"),
-            atom!("textPath"),
-        ];
-    }
+    const SPECIAL_SVG_ELEMENTS: [Atom; 6] = [
+        atom!("svg"),
+        atom!("a"),
+        atom!("g"),
+        atom!("use"),
+        atom!("tspan"),
+        atom!("textPath"),
+    ];
 
     // https://drafts.csswg.org/css-display/#unbox-html
     if element.is_html_element() {