diff --git a/assets/examples/ruby/promises.rb b/assets/examples/ruby/promises.rb
index a3910af..54560e3 100644
--- a/assets/examples/ruby/promises.rb
+++ b/assets/examples/ruby/promises.rb
@@ -1,13 +1,21 @@
-a = get_player_name
-b = a
-puts '0'
-puts a.await
-puts '1'
-u = get_player_name
-puts b.await
-puts '2'
-z = get_player_name
-puts z
-puts z.await
-puts "end"
+def async_fun
+  async do
+    a = get_player_name
+    b = a
+    puts '0'
+    puts a.await
+    puts '1'
+    u = get_player_name
+    puts b.await
+    puts '2'
+    z = get_player_name
+    puts z
+    puts z.await
+    puts "end"
+  end
+end
+
+async_fun.await
+puts "after await"
+
 quit
diff --git a/src/runtimes/ruby.rs b/src/runtimes/ruby.rs
index 075e036..7477cb0 100644
--- a/src/runtimes/ruby.rs
+++ b/src/runtimes/ruby.rs
@@ -213,6 +213,19 @@ impl TryConvert for BevyEntity {
 #[magnus::wrap(class = "Bevy::Vec3")]
 pub struct BevyVec3(pub Vec3);
 
+pub fn async_function() {
+    let ruby = Ruby::get().unwrap();
+    let fiber = ruby
+        .fiber_new_from_fn(Default::default(), move |ruby, _args, _block| {
+            let p = ruby.block_proc().unwrap();
+            p.call::<_, value::Value>(()).unwrap();
+
+            Ok(())
+        })
+        .unwrap();
+    fiber.resume::<_, magnus::Value>(()).unwrap();
+}
+
 impl BevyVec3 {
     pub fn new(x: f32, y: f32, z: f32) -> Self {
         Self(Vec3::new(x, y, z))
@@ -291,6 +304,8 @@ impl Default for RubyRuntime {
                 vec3.define_method("x", method!(BevyVec3::x, 0))?;
                 vec3.define_method("y", method!(BevyVec3::y, 0))?;
                 vec3.define_method("z", method!(BevyVec3::z, 0))?;
+
+                ruby.define_global_function("async", function!(async_function, 0));
                 Ok::<(), ScriptingError>(())
             }))
             .expect("Failed to define builtin types");