diff --git a/crates/napi/src/env.rs b/crates/napi/src/env.rs
index 1b5c59dd..4994393f 100644
--- a/crates/napi/src/env.rs
+++ b/crates/napi/src/env.rs
@@ -672,7 +672,7 @@ impl Env {
   }
 
   /// This API throws a JavaScript SyntaxError with the text provided.
-  #[cfg(feature = "experimental")]
+  #[cfg(feature = "napi9")]
   pub fn throw_syntax_error(&self, msg: &str, code: Option<&str>) -> Result<()> {
     let code = code.and_then(|s| CString::new(s).ok());
     let msg = CString::new(msg)?;
diff --git a/crates/napi/src/error.rs b/crates/napi/src/error.rs
index 6f8a5d79..ce4db4cc 100644
--- a/crates/napi/src/error.rs
+++ b/crates/napi/src/error.rs
@@ -213,7 +213,7 @@ pub struct JsTypeError<S: AsRef<str> = Status>(Error<S>);
 
 pub struct JsRangeError<S: AsRef<str> = Status>(Error<S>);
 
-#[cfg(feature = "experimental")]
+#[cfg(feature = "napi9")]
 pub struct JsSyntaxError<S: AsRef<str> = Status>(Error<S>);
 
 macro_rules! impl_object_methods {
@@ -307,7 +307,7 @@ macro_rules! impl_object_methods {
 impl_object_methods!(JsError, sys::napi_create_error);
 impl_object_methods!(JsTypeError, sys::napi_create_type_error);
 impl_object_methods!(JsRangeError, sys::napi_create_range_error);
-#[cfg(feature = "experimental")]
+#[cfg(feature = "napi9")]
 impl_object_methods!(JsSyntaxError, sys::node_api_create_syntax_error);
 
 #[doc(hidden)]
diff --git a/crates/sys/src/functions.rs b/crates/sys/src/functions.rs
index 91fa2410..eafdb768 100644
--- a/crates/sys/src/functions.rs
+++ b/crates/sys/src/functions.rs
@@ -712,18 +712,6 @@ mod napi9 {
         length: usize,
         result: *mut napi_value,
       ) -> napi_status;
-    }
-  );
-}
-
-#[cfg(feature = "experimental")]
-mod experimental {
-  use std::os::raw::c_char;
-
-  use super::super::types::*;
-
-  generate!(
-    extern "C" {
       fn node_api_get_module_file_name(env: napi_env, result: *mut *const c_char) -> napi_status;
       fn node_api_create_syntax_error(
         env: napi_env,
@@ -740,6 +728,37 @@ mod experimental {
   );
 }
 
+#[cfg(feature = "experimental")]
+mod experimental {
+  use std::os::raw::{c_char, c_void};
+
+  use super::super::types::*;
+
+  generate!(
+    extern "C" {
+      fn node_api_create_external_string_latin1(
+        env: napi_env,
+        str_: *const c_char,
+        length: usize,
+        napi_finalize: napi_finalize,
+        finalize_hint: *mut c_void,
+        result: *mut napi_value,
+        copied: *mut bool,
+      ) -> napi_status;
+
+      fn node_api_create_external_string_utf16(
+        env: napi_env,
+        str_: *const u16,
+        length: usize,
+        napi_finalize: napi_finalize,
+        finalize_hint: *mut c_void,
+        result: *mut napi_value,
+        copied: *mut bool,
+      ) -> napi_status;
+    }
+  );
+}
+
 #[cfg(feature = "experimental")]
 pub use experimental::*;
 pub use napi1::*;