diff --git a/compiler/rustc_middle/src/mir/mod.rs b/compiler/rustc_middle/src/mir/mod.rs
index 38d4c5b4bd10..e40227530cde 100644
--- a/compiler/rustc_middle/src/mir/mod.rs
+++ b/compiler/rustc_middle/src/mir/mod.rs
@@ -1736,7 +1736,7 @@ pub struct Place<'tcx> {
     pub projection: &'tcx List<PlaceElem<'tcx>>,
 }
 
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 static_assert_size!(Place<'_>, 16);
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -2062,7 +2062,7 @@ pub enum Operand<'tcx> {
     Constant(Box<Constant<'tcx>>),
 }
 
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 static_assert_size!(Operand<'_>, 24);
 
 impl<'tcx> Debug for Operand<'tcx> {
@@ -2200,7 +2200,7 @@ pub enum Rvalue<'tcx> {
     Aggregate(Box<AggregateKind<'tcx>>, Vec<Operand<'tcx>>),
 }
 
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 static_assert_size!(Rvalue<'_>, 40);
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
@@ -2226,7 +2226,7 @@ pub enum AggregateKind<'tcx> {
     Generator(DefId, SubstsRef<'tcx>, hir::Movability),
 }
 
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 static_assert_size!(AggregateKind<'_>, 48);
 
 #[derive(Copy, Clone, Debug, PartialEq, PartialOrd, Eq, TyEncodable, TyDecodable, Hash, HashStable)]
diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs
index 9f06bdcc135b..568682cc3e4e 100644
--- a/compiler/rustc_parse/src/parser/attr_wrapper.rs
+++ b/compiler/rustc_parse/src/parser/attr_wrapper.rs
@@ -34,7 +34,7 @@ pub struct AttrWrapper {
 
 // This struct is passed around very frequently,
 // so make sure it doesn't accidentally get larger
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 rustc_data_structures::static_assert_size!(AttrWrapper, 16);
 
 impl AttrWrapper {
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 733bedfdde9b..34f9c0a8187a 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -69,7 +69,7 @@ crate struct Context<'tcx> {
 }
 
 // `Context` is cloned a lot, so we don't want the size to grow unexpectedly.
-#[cfg(target_arch = "x86_64")]
+#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
 rustc_data_structures::static_assert_size!(Context<'_>, 104);
 
 /// Shared mutable state used in [`Context`] and elsewhere.