diff --git a/napi/src/env.rs b/napi/src/env.rs
index 9438f35a..5a982b21 100644
--- a/napi/src/env.rs
+++ b/napi/src/env.rs
@@ -344,13 +344,15 @@ impl Env {
 
   pub fn create_function(&self, name: &str, callback: Callback) -> Result<JsFunction> {
     let mut raw_result = ptr::null_mut();
+    let name = CString::new(name.to_owned())?;
+    let len = name.as_bytes().len();
     check_status(unsafe {
       sys::napi_create_function(
         self.0,
-        name.as_ptr() as *const c_char,
-        name.len() as _,
+        name.into_raw(),
+        len,
         Some(callback),
-        callback as *mut c_void,
+        ptr::null_mut(),
         &mut raw_result,
       )
     })?;
diff --git a/napi/src/js_values/mod.rs b/napi/src/js_values/mod.rs
index 227fc9e1..65387f5f 100644
--- a/napi/src/js_values/mod.rs
+++ b/napi/src/js_values/mod.rs
@@ -257,7 +257,7 @@ macro_rules! impl_object_methods {
       where
         T: NapiValue,
       {
-        let key = CString::new(name)?;
+        let key = CString::new(name.to_owned())?;
         check_status(unsafe {
           sys::napi_set_named_property(self.0.env, self.0.value, key.as_ptr(), value.raw())
         })