diff --git a/crates/fayalite/src/sim/interpreter.rs b/crates/fayalite/src/sim/interpreter.rs
index de582f0..35a25d0 100644
--- a/crates/fayalite/src/sim/interpreter.rs
+++ b/crates/fayalite/src/sim/interpreter.rs
@@ -7,7 +7,7 @@ use crate::{
     intern::{Intern, Interned, Memoize},
     source_location::SourceLocation,
     ty::CanonicalType,
-    util::{get_many_mut, HashMap, HashSet},
+    util::{HashMap, HashSet},
 };
 use bitvec::{boxed::BitBox, slice::BitSlice};
 use num_bigint::BigInt;
@@ -2073,21 +2073,21 @@ pub(crate) struct BorrowedStatePart<'a, K: StatePartKind> {
 }
 
 impl<
-        'a,
-        K: StatePartKind<
-            BorrowedState<'a>: DerefMut<Target: IndexMut<usize, Output = T> + BorrowMut<[T]>>,
-        >,
-        T,
-    > BorrowedStatePart<'a, K>
+    'a,
+    K: StatePartKind<
+        BorrowedState<'a>: DerefMut<Target: IndexMut<usize, Output = T> + BorrowMut<[T]>>,
+    >,
+    T,
+> BorrowedStatePart<'a, K>
 {
-    pub(crate) fn get_many_mut<const N: usize>(
+    pub(crate) fn get_disjoint_mut<const N: usize>(
         &mut self,
         indexes: [StatePartIndex<K>; N],
     ) -> [&mut T; N] {
-        get_many_mut(
-            (*self.value).borrow_mut(),
-            indexes.map(|v| v.value as usize),
-        )
+        (*self.value)
+            .borrow_mut()
+            .get_disjoint_mut(indexes.map(|v| v.value as usize))
+            .expect("indexes are disjoint")
     }
 }
 
@@ -2568,7 +2568,7 @@ impl_insns! {
         src: StatePartIndex<StatePartKindBigSlots>,
     } => {
         if dest != src {
-            let [dest, src] = state.big_slots.get_many_mut([dest, src]);
+            let [dest, src] = state.big_slots.get_disjoint_mut([dest, src]);
             dest.clone_from(src);
         }
         next!();
@@ -2590,7 +2590,7 @@ impl_insns! {
     } => {
         if let Some(src) = state.eval_array_indexed(src) {
             if dest != src {
-                let [dest, src] = state.big_slots.get_many_mut([dest, src]);
+                let [dest, src] = state.big_slots.get_disjoint_mut([dest, src]);
                 dest.clone_from(src);
             }
         } else {
@@ -2619,7 +2619,7 @@ impl_insns! {
     } => {
         if let Some(dest) = state.eval_array_indexed(dest) {
             if dest != src {
-                let [dest, src] = state.big_slots.get_many_mut([dest, src]);
+                let [dest, src] = state.big_slots.get_disjoint_mut([dest, src]);
                 dest.clone_from(src);
             }
         }
diff --git a/crates/fayalite/src/util.rs b/crates/fayalite/src/util.rs
index 233867e..4670a1f 100644
--- a/crates/fayalite/src/util.rs
+++ b/crates/fayalite/src/util.rs
@@ -35,8 +35,8 @@ pub use scoped_ref::ScopedRef;
 
 #[doc(inline)]
 pub use misc::{
-    get_many_mut, interned_bit, iter_eq_by, BitSliceWriteWithBase, DebugAsDisplay,
-    DebugAsRawString, MakeMutSlice, RcWriter,
+    BitSliceWriteWithBase, DebugAsDisplay, DebugAsRawString, MakeMutSlice, RcWriter, interned_bit,
+    iter_eq_by,
 };
 
 pub mod job_server;
diff --git a/crates/fayalite/src/util/misc.rs b/crates/fayalite/src/util/misc.rs
index f482eaa..99b7343 100644
--- a/crates/fayalite/src/util/misc.rs
+++ b/crates/fayalite/src/util/misc.rs
@@ -163,22 +163,6 @@ impl fmt::UpperHex for BitSliceWriteWithBase<'_> {
     }
 }
 
-#[inline]
-#[track_caller]
-pub fn get_many_mut<T, const N: usize>(slice: &mut [T], indexes: [usize; N]) -> [&mut T; N] {
-    for i in 0..N {
-        for j in 0..i {
-            assert!(indexes[i] != indexes[j], "duplicate index");
-        }
-        assert!(indexes[i] < slice.len(), "index out of bounds");
-    }
-    // Safety: checked that no indexes are duplicates and no indexes are out of bounds
-    unsafe {
-        let base = slice.as_mut_ptr(); // convert to a raw pointer before loop to avoid aliasing with &mut [T]
-        std::array::from_fn(|i| &mut *base.add(indexes[i]))
-    }
-}
-
 #[derive(Clone, Default)]
 pub struct RcWriter(Rc<Cell<Vec<u8>>>);