diff --git a/crates/nargo_cli/tests/execution_success/closures_mut_ref/src/main.nr b/crates/nargo_cli/tests/execution_success/closures_mut_ref/src/main.nr
index 1f439a3b43d..2888745a96e 100644
--- a/crates/nargo_cli/tests/execution_success/closures_mut_ref/src/main.nr
+++ b/crates/nargo_cli/tests/execution_success/closures_mut_ref/src/main.nr
@@ -15,4 +15,17 @@ fn main(mut x: Field) {
     add2(&mut x);
     assert(x == 3);
 
+    issue_2120();
 }
+
+// https://github.com/noir-lang/noir/issues/2120
+fn issue_2120() {
+    let x1 = &mut 42;
+    let set_x1 = |y| { *x1 = y; };
+
+    assert(*x1 == 42);
+    set_x1(44);
+    assert(*x1 == 44);
+    set_x1(*x1);
+    assert(*x1 == 44);
+}
\ No newline at end of file
diff --git a/crates/noirc_frontend/src/monomorphization/mod.rs b/crates/noirc_frontend/src/monomorphization/mod.rs
index 4a04cb7b58e..466a3f95e81 100644
--- a/crates/noirc_frontend/src/monomorphization/mod.rs
+++ b/crates/noirc_frontend/src/monomorphization/mod.rs
@@ -1126,7 +1126,7 @@ impl<'interner> Monomorphizer<'interner> {
         });
 
         let location = None; // TODO: This should match the location of the lambda expression
-        let mutable = false;
+        let mutable = true;
         let definition = Definition::Local(env_local_id);
 
         let env_ident = ast::Ident {