diff --git a/src/platform_impl/macos.rs b/src/platform_impl/macos.rs
index 4b107a62..99edeaed 100644
--- a/src/platform_impl/macos.rs
+++ b/src/platform_impl/macos.rs
@@ -5,6 +5,6 @@ use tauri::{
     plugin::{self, TauriPlugin},
     Runtime,
 };
-pub fn init<R: Runtime>(f: Box<SingleInstanceCallback>) -> TauriPlugin<R> {
+pub fn init<R: Runtime>(f: Box<SingleInstanceCallback<R>>) -> TauriPlugin<R> {
     plugin::Builder::new("single-instance").build()
 }