diff --git a/clippy_utils/src/hir_utils.rs b/clippy_utils/src/hir_utils.rs
index 74ef2c1bebb..793e3cc58c2 100644
--- a/clippy_utils/src/hir_utils.rs
+++ b/clippy_utils/src/hir_utils.rs
@@ -16,6 +16,10 @@ use rustc_middle::ty::TypeckResults;
 use rustc_span::{sym, Symbol};
 use std::hash::{Hash, Hasher};
 
+/// Callback that is called when two expressions are not equal in the sense of `SpanlessEq`, but
+/// other conditions would make them equal.
+type SpanlessEqCallback<'a> = dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a;
+
 /// Type used to check whether two ast are the same. This is different from the
 /// operator `==` on ast types as this operator would compare true equality with
 /// ID and span.
@@ -26,7 +30,7 @@ pub struct SpanlessEq<'a, 'tcx> {
     cx: &'a LateContext<'tcx>,
     maybe_typeck_results: Option<(&'tcx TypeckResults<'tcx>, &'tcx TypeckResults<'tcx>)>,
     allow_side_effects: bool,
-    expr_fallback: Option<Box<dyn FnMut(&Expr<'_>, &Expr<'_>) -> bool + 'a>>,
+    expr_fallback: Option<Box<SpanlessEqCallback<'a>>>,
 }
 
 impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
diff --git a/src/driver.rs b/src/driver.rs
index d8e0b8ef39a..96d542cfe10 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -153,7 +153,8 @@ You can use tool lints to allow or deny lints from your code, eg.:
 
 const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust-clippy/issues/new";
 
-static ICE_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> = LazyLock::new(|| {
+type PanicCallback = dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static;
+static ICE_HOOK: LazyLock<Box<PanicCallback>> = LazyLock::new(|| {
     let hook = panic::take_hook();
     panic::set_hook(Box::new(|info| report_clippy_ice(info, BUG_REPORT_URL)));
     hook