diff --git a/compio-runtime/Cargo.toml b/compio-runtime/Cargo.toml
index b2a64c06..61721555 100644
--- a/compio-runtime/Cargo.toml
+++ b/compio-runtime/Cargo.toml
@@ -56,7 +56,8 @@ libc = { workspace = true }
 windows-sys = { workspace = true, features = ["Win32_UI_WindowsAndMessaging"] }
 
 [target.'cfg(target_os = "macos")'.dev-dependencies]
-core-foundation = "0.9"
+core-foundation = "0.9.4"
+block2 = "0.4.0"
 
 [features]
 event = ["dep:cfg-if", "compio-buf/arrayvec"]
diff --git a/compio-runtime/tests/custom_loop.rs b/compio-runtime/tests/custom_loop.rs
index 66fc5f8c..1b9e5ec3 100644
--- a/compio-runtime/tests/custom_loop.rs
+++ b/compio-runtime/tests/custom_loop.rs
@@ -3,12 +3,14 @@
 fn cf_run_loop() {
     use std::{future::Future, os::raw::c_void, time::Duration};
 
+    use block2::{Block, ConcreteBlock};
     use compio_driver::AsRawFd;
-    use compio_runtime::Runtime;
+    use compio_runtime::{event::Event, Runtime};
     use core_foundation::{
         base::TCFType,
         filedescriptor::{kCFFileDescriptorReadCallBack, CFFileDescriptor, CFFileDescriptorRef},
-        runloop::{kCFRunLoopDefaultMode, CFRunLoop},
+        runloop::{kCFRunLoopDefaultMode, CFRunLoop, CFRunLoopRef},
+        string::CFStringRef,
     };
 
     struct CFRunLoopRuntime {
@@ -73,11 +75,24 @@ fn cf_run_loop() {
 
     let runtime = CFRunLoopRuntime::new();
 
-    let res = runtime.block_on(async {
-        compio_runtime::time::sleep(Duration::from_secs(1)).await;
-        1
+    runtime.block_on(async {
+        let event = Event::new();
+        let block = ConcreteBlock::new(|| {
+            event.handle().notify();
+        });
+        extern "C" {
+            fn CFRunLoopPerformBlock(rl: CFRunLoopRef, mode: CFStringRef, block: &Block<(), ()>);
+        }
+        let run_loop = CFRunLoop::get_current();
+        unsafe {
+            CFRunLoopPerformBlock(
+                run_loop.as_concrete_TypeRef(),
+                kCFRunLoopDefaultMode,
+                &block,
+            );
+        }
+        event.wait().await;
     });
-    assert_eq!(res, 1);
 }
 
 #[cfg(windows)]