diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 640f31355ac33..71d1829f76584 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -852,7 +852,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(mir_opt_level, Some(4));
     tracked!(mir_preserve_ub, true);
     tracked!(move_size_limit, Some(4096));
-    tracked!(mutable_noalias, false);
     tracked!(next_solver, NextSolverConfig { coherence: true, globally: true });
     tracked!(no_generate_arange_section, true);
     tracked!(no_link, true);
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 2f44b4c102486..d508c963791d4 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -2568,8 +2568,6 @@ options! {
         "Whether to remove some of the MIR debug info from methods.  Default: None"),
     move_size_limit: Option<usize> = (None, parse_opt_number, [TRACKED],
         "the size at which the `large_assignments` lint starts to be emitted"),
-    mutable_noalias: bool = (true, parse_bool, [TRACKED],
-        "emit noalias metadata for mutable references (default: yes)"),
     namespaced_crates: bool = (false, parse_bool, [TRACKED],
         "allow crates to be namespaced by other crates (default: no)"),
     next_solver: NextSolverConfig = (NextSolverConfig::default(), parse_next_solver_config, [TRACKED],
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index 8873fb13efe03..1cc128c9b46eb 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -366,11 +366,6 @@ fn arg_attrs_for_rust_scalar<'tcx>(
             // See https://github.com/rust-lang/unsafe-code-guidelines/issues/326
             let noalias_for_box = tcx.sess.opts.unstable_opts.box_noalias;
 
-            // LLVM prior to version 12 had known miscompiles in the presence of noalias attributes
-            // (see #54878), so it was conditionally disabled, but we don't support earlier
-            // versions at all anymore. We still support turning it off using -Zmutable-noalias.
-            let noalias_mut_ref = tcx.sess.opts.unstable_opts.mutable_noalias;
-
             // `&T` where `T` contains no `UnsafeCell<U>` is immutable, and can be marked as both
             // `readonly` and `noalias`, as LLVM's definition of `noalias` is based solely on memory
             // dependencies rather than pointer equality. However this only applies to arguments,
@@ -379,7 +374,7 @@ fn arg_attrs_for_rust_scalar<'tcx>(
             // `&mut T` and `Box<T>` where `T: Unpin` are unique and hence `noalias`.
             let no_alias = match kind {
                 PointerKind::SharedRef { frozen } => frozen,
-                PointerKind::MutableRef { unpin } => unpin && noalias_mut_ref,
+                PointerKind::MutableRef { unpin } => unpin,
                 PointerKind::Box { unpin, global } => unpin && global && noalias_for_box,
             };
             // We can never add `noalias` in return position; that LLVM attribute has some very surprising semantics
diff --git a/tests/codegen-llvm/noalias-flag.rs b/tests/codegen-llvm/noalias-flag.rs
deleted file mode 100644
index 67ba68ee6f80a..0000000000000
--- a/tests/codegen-llvm/noalias-flag.rs
+++ /dev/null
@@ -1,23 +0,0 @@
-//@ compile-flags: -Copt-level=3 -Zmutable-noalias=no
-
-#![crate_type = "lib"]
-
-// `-Zmutable-noalias=no` should disable noalias on mut refs...
-
-// CHECK-LABEL: @test_mut_ref(
-// CHECK-NOT: noalias
-// CHECK-SAME: %x
-#[no_mangle]
-pub fn test_mut_ref(x: &mut i32) -> &mut i32 {
-    x
-}
-
-// ...but not on shared refs
-
-// CHECK-LABEL: @test_ref(
-// CHECK-SAME: noalias
-// CHECK-SAME: %x
-#[no_mangle]
-pub fn test_ref(x: &i32) -> &i32 {
-    x
-}
diff --git a/tests/codegen-llvm/noalias-refcell.rs b/tests/codegen-llvm/noalias-refcell.rs
index b37adf92b9cc3..87f3ea624700a 100644
--- a/tests/codegen-llvm/noalias-refcell.rs
+++ b/tests/codegen-llvm/noalias-refcell.rs
@@ -1,4 +1,4 @@
-//@ compile-flags: -Copt-level=3 -C no-prepopulate-passes -Z mutable-noalias=yes
+//@ compile-flags: -Copt-level=3 -C no-prepopulate-passes
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen-llvm/noalias-rwlockreadguard.rs b/tests/codegen-llvm/noalias-rwlockreadguard.rs
index c676dc32399da..7eacf6c792eb8 100644
--- a/tests/codegen-llvm/noalias-rwlockreadguard.rs
+++ b/tests/codegen-llvm/noalias-rwlockreadguard.rs
@@ -1,4 +1,4 @@
-//@ compile-flags: -Copt-level=3 -C no-prepopulate-passes -Z mutable-noalias=yes
+//@ compile-flags: -Copt-level=3 -C no-prepopulate-passes
 
 #![crate_type = "lib"]
 
diff --git a/tests/codegen-llvm/noalias-unpin.rs b/tests/codegen-llvm/noalias-unpin.rs
index 30a8b399b9798..b164495e50724 100644
--- a/tests/codegen-llvm/noalias-unpin.rs
+++ b/tests/codegen-llvm/noalias-unpin.rs
@@ -1,4 +1,4 @@
-//@ compile-flags: -Copt-level=3 -Z mutable-noalias=yes
+//@ compile-flags: -Copt-level=3
 
 #![crate_type = "lib"]