diff --git a/src/Simulation/qdk_sim_rs/benches/c_api_benchmark.rs b/src/Simulation/qdk_sim_rs/benches/c_api_benchmark.rs
index f0e52c87289..bf01f3109fc 100644
--- a/src/Simulation/qdk_sim_rs/benches/c_api_benchmark.rs
+++ b/src/Simulation/qdk_sim_rs/benches/c_api_benchmark.rs
@@ -51,8 +51,7 @@ fn with_test_suite<T: criterion::measurement::Measurement>(
 fn ideal(c: &mut Criterion) {
     let mut sim_id: usize = 0;
     unsafe {
-        let repr = CString::new("mixed").unwrap();
-        let _err = c_api::init(3, repr.as_ptr(), &mut sim_id);
+        let _err = c_api::init(3, "mixed\0".as_ptr() as _, &mut sim_id);
     }
     let mut group = c.benchmark_group("ideal");
     with_test_suite(sim_id, &mut group);
@@ -63,8 +62,7 @@ fn ideal(c: &mut Criterion) {
 fn noisy(c: &mut Criterion) {
     let mut sim_id: usize = 0;
     unsafe {
-        let repr = CString::new("mixed").unwrap();
-        let _err = c_api::init(3, repr.as_ptr(), &mut sim_id);
+        let _err = c_api::init(3, "mixed\0".as_ptr() as _, &mut sim_id);
     }
     // NB: The C API is not in general safe.
     unsafe {
diff --git a/src/Simulation/qdk_sim_rs/src/c_api.rs b/src/Simulation/qdk_sim_rs/src/c_api.rs
index 1024a3f1dc9..47e5ba77a51 100644
--- a/src/Simulation/qdk_sim_rs/src/c_api.rs
+++ b/src/Simulation/qdk_sim_rs/src/c_api.rs
@@ -581,8 +581,7 @@ mod tests {
     fn ry_runs_without_error_or_panic() -> Result<(), (String, i64)> {
         unsafe {
             let mut sim_id: usize = 0;
-            let mixed = CString::new("mixed").unwrap();
-            as_result(c_api::init(3, mixed.as_ptr(), &mut sim_id))?;
+            as_result(c_api::init(3, "mixed\0".as_ptr() as _, &mut sim_id))?;
             as_result(c_api::ry(sim_id, 1.234, 1))?;
             as_result(c_api::destroy(sim_id))?;
             Ok(())
@@ -593,10 +592,8 @@ mod tests {
     fn teleport() -> Result<(), (String, i64)> {
         unsafe {
             let mut sim_id: usize = 0;
-            let mixed = CString::new("mixed").unwrap();
-            let ideal = CString::new("ideal").unwrap();
-            as_result(c_api::init(3, mixed.as_ptr(), &mut sim_id))?;
-            as_result(c_api::set_noise_model_by_name(sim_id, ideal.as_ptr()))?;
+            as_result(c_api::init(3, "mixed\0".as_ptr() as _, &mut sim_id))?;
+            as_result(c_api::set_noise_model_by_name(sim_id, "ideal\0".as_ptr() as _))?;
 
             let idx_msg = 0;
             let idx_here = 1;