diff --git a/napi-derive/src/lib.rs b/napi-derive/src/lib.rs
index 744bbf35..6954c61b 100644
--- a/napi-derive/src/lib.rs
+++ b/napi-derive/src/lib.rs
@@ -204,7 +204,7 @@ fn get_execute_js_code(
       Err(e) => {
         let message = format!("{}", e);
         unsafe {
-          napi::sys::napi_throw_error(raw_env, ptr::null(), CString::from_vec_unchecked(message.into()).as_ptr() as *const c_char);
+          napi::sys::napi_throw_error(raw_env, ptr::null(), CString::from_vec_unchecked(message.into()).into_raw());
         }
         ptr::null_mut()
       }
diff --git a/napi/src/env.rs b/napi/src/env.rs
index 462744b9..16c842f2 100644
--- a/napi/src/env.rs
+++ b/napi/src/env.rs
@@ -368,11 +368,7 @@ impl Env {
 
   pub fn throw_error(&self, msg: &str) -> Result<()> {
     check_status(unsafe {
-      sys::napi_throw_error(
-        self.0,
-        ptr::null(),
-        CString::from_vec_unchecked(msg.into()).as_ptr() as *const _,
-      )
+      sys::napi_throw_error(self.0, ptr::null(), CString::new(msg)?.into_raw())
     })
   }
 
diff --git a/napi/src/js_values/mod.rs b/napi/src/js_values/mod.rs
index 65387f5f..6b476b54 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.to_owned())?;
+        let key = CString::new(name)?;
         check_status(unsafe {
           sys::napi_set_named_property(self.0.env, self.0.value, key.as_ptr(), value.raw())
         })
@@ -273,12 +273,9 @@ macro_rules! impl_object_methods {
         })?;
         T::from_raw(self.0.env, raw_value)
       }
-      pub fn has_named_property<S>(&self, name: S) -> Result<bool>
-      where
-        S: AsRef<str>,
-      {
+      pub fn has_named_property(&self, name: &str) -> Result<bool> {
         let mut result = false;
-        let key = CString::new(name.as_ref())?;
+        let key = CString::new(name)?;
         check_status(unsafe {
           sys::napi_has_named_property(self.0.env, self.0.value, key.as_ptr(), &mut result)
         })?;
@@ -299,7 +296,7 @@ macro_rules! impl_object_methods {
         let key_str = CString::new(name)?;
         let mut js_key = ptr::null_mut();
         check_status(unsafe {
-          sys::napi_create_string_utf8(self.0.env, key_str.as_ptr(), name.len() as _, &mut js_key)
+          sys::napi_create_string_utf8(self.0.env, key_str.as_ptr(), name.len(), &mut js_key)
         })?;
         check_status(unsafe {
           sys::napi_delete_property(self.0.env, self.0.value, js_key, &mut result)
@@ -311,7 +308,7 @@ macro_rules! impl_object_methods {
         let string = CString::new(key)?;
         let mut js_key = ptr::null_mut();
         check_status(unsafe {
-          sys::napi_create_string_utf8(self.0.env, string.as_ptr(), key.len() as _, &mut js_key)
+          sys::napi_create_string_utf8(self.0.env, string.as_ptr(), key.len(), &mut js_key)
         })?;
         check_status(unsafe {
           sys::napi_has_own_property(self.0.env, self.0.value, js_key, &mut result)
diff --git a/napi/src/js_values/object_property.rs b/napi/src/js_values/object_property.rs
index f0c45390..fff003f8 100644
--- a/napi/src/js_values/object_property.rs
+++ b/napi/src/js_values/object_property.rs
@@ -37,7 +37,7 @@ impl<'env> Property<'env> {
     let string_value = CString::new(name)?;
     let mut result = ptr::null_mut();
     check_status(unsafe {
-      sys::napi_create_string_utf8(env.0, string_value.as_ptr(), name.len() as _, &mut result)
+      sys::napi_create_string_utf8(env.0, string_value.as_ptr(), name.len(), &mut result)
     })?;
     Ok(Property {
       name,
diff --git a/napi/src/lib.rs b/napi/src/lib.rs
index be89dead..eac95756 100644
--- a/napi/src/lib.rs
+++ b/napi/src/lib.rs
@@ -188,7 +188,7 @@ macro_rules! register_module {
               raw_env,
               ptr::null(),
               CString::from_vec_unchecked(format!("Error initializing module: {}", e).into())
-                .as_ptr() as *const _,
+                .into_raw() as *const _,
             )
           };
           ptr::null_mut()