diff --git a/rust-version b/rust-version
index 721d6df0f1..e32968d817 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-5ac0b2d0219de2fd6fef86c69ef0cfa1e6c36f3b
+ee03c286cfdca26fa5b2a4ee40957625d2c826ff
diff --git a/src/diagnostics.rs b/src/diagnostics.rs
index 4683965159..03428b081c 100644
--- a/src/diagnostics.rs
+++ b/src/diagnostics.rs
@@ -527,8 +527,7 @@ impl<'mir, 'tcx> MiriMachine<'mir, 'tcx> {
     pub fn emit_diagnostic(&self, e: NonHaltingDiagnostic) {
         use NonHaltingDiagnostic::*;
 
-        let stacktrace =
-            MiriInterpCx::generate_stacktrace_from_stack(self.threads.active_thread_stack());
+        let stacktrace = Frame::generate_stacktrace_from_stack(self.threads.active_thread_stack());
         let (stacktrace, _was_pruned) = prune_stacktrace(stacktrace, self);
 
         let (title, diag_level) = match &e {
diff --git a/src/helpers.rs b/src/helpers.rs
index 76f4b77c8f..c12fe0e086 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -413,7 +413,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 .ok_or_else(|| err_ub_format!("callee has fewer arguments than expected"))?;
             // Make the local live, and insert the initial value.
             this.storage_live(local)?;
-            let callee_arg = this.local_to_place(this.frame_idx(), local)?;
+            let callee_arg = this.local_to_place(local)?;
             this.write_immediate(*arg, &callee_arg)?;
         }
         if callee_args.next().is_some() {
diff --git a/src/machine.rs b/src/machine.rs
index 4dbb814fc2..7e5518392d 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -1488,14 +1488,13 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
 
     fn after_local_allocated(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
-        frame: usize,
         local: mir::Local,
         mplace: &MPlaceTy<'tcx, Provenance>,
     ) -> InterpResult<'tcx> {
         let Some(Provenance::Concrete { alloc_id, .. }) = mplace.ptr().provenance else {
             panic!("after_local_allocated should only be called on fresh allocations");
         };
-        let local_decl = &ecx.active_thread_stack()[frame].body.local_decls[local];
+        let local_decl = &ecx.frame().body.local_decls[local];
         let span = local_decl.source_info.span;
         ecx.machine.allocation_spans.borrow_mut().insert(alloc_id, (span, None));
         Ok(())
diff --git a/tests/pass/shims/time-with-isolation.stdout b/tests/pass/shims/time-with-isolation.stdout
index f3d071e001..ff5889bacd 100644
--- a/tests/pass/shims/time-with-isolation.stdout
+++ b/tests/pass/shims/time-with-isolation.stdout
@@ -1,2 +1,2 @@
-The loop took around 7s
+The loop took around 12s
 (It's fine for this number to change when you `--bless` this test.)