diff --git a/Cargo.toml b/Cargo.toml
index dd826bf..092efff 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,6 +22,7 @@ php-tokio = "0.1.4"
 
 [dev-dependencies]
 skeptic = "0.13"
+reqwest = "0.11.22"
 
 [build-dependencies]
 anyhow = "1"
diff --git a/guide/src/SUMMARY.md b/guide/src/SUMMARY.md
index 2ca6c5f..4108d1b 100644
--- a/guide/src/SUMMARY.md
+++ b/guide/src/SUMMARY.md
@@ -24,6 +24,7 @@
   - [Class Object](./types/class_object.md)
   - [Closure](./types/closure.md)
   - [Functions & methods](./types/functions.md)
+  - [Async futures](./macros/impl.md#async)
 - [Macros](./macros/index.md)
   - [Module](./macros/module.md)
   - [Module Startup Function](./macros/module_startup.md)
diff --git a/guide/src/macros/impl.md b/guide/src/macros/impl.md
index e1adc50..61b0e70 100644
--- a/guide/src/macros/impl.md
+++ b/guide/src/macros/impl.md
@@ -213,6 +213,8 @@ pub extern "C" fn request_shutdown(_type: i32, _module_number: i32) -> i32 {
 pub fn get_module(module: ModuleBuilder) -> ModuleBuilder {
     module.request_shutdown_function(request_shutdown)
 }
+
+# fn main() {}
 ```
 
 Here's the async PHP code we use to interact with the Rust class we just exposed.