diff --git a/Cargo.lock b/Cargo.lock
index d25923a..c676255 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -122,6 +122,7 @@ name = "chapter12"
 version = "0.1.0"
 dependencies = [
  "lib",
+ "signal-hook",
 ]
 
 [[package]]
@@ -887,11 +888,21 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "signal-hook"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "470c5a6397076fae0094aaf06a08e6ba6f37acb77d3b1b91ea92b4d6c8650c39"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
 [[package]]
 name = "signal-hook-registry"
-version = "1.3.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16f1d0fef1604ba8f7a073c7e701f213e056707210e9020af4528e0101ce11a6"
+checksum = "e51e73328dc4ac0c7ccbda3a494dfa03df1de2f46018127f60c693f2648455b0"
 dependencies = [
  "libc",
 ]
diff --git a/chapter12/Cargo.toml b/chapter12/Cargo.toml
index e37613d..79003e9 100644
--- a/chapter12/Cargo.toml
+++ b/chapter12/Cargo.toml
@@ -7,4 +7,12 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-lib = { path = "../lib" }
\ No newline at end of file
+lib = { path = "../lib" }
+tokio = { version = "1.8.1", features = ["full"] }
+signal-hook = "0.3.9"
+signal-hook-tokio = { version = "0.3.0", features = ["futures-v0_3"] }
+futures = "0.3.15"
+
+[[bin]]
+name = "12_4"
+path = "src/12_4/main.rs"
diff --git a/chapter12/src/12_4/main.rs b/chapter12/src/12_4/main.rs
new file mode 100644
index 0000000..55c38ca
--- /dev/null
+++ b/chapter12/src/12_4/main.rs
@@ -0,0 +1,25 @@
+use futures::stream::StreamExt;
+use signal_hook::consts::signal::*;
+use signal_hook_tokio::Signals;
+use std::io::Error;
+
+#[tokio::main]
+async fn main() -> Result<(), Error> {
+    let signals: Signals = Signals::new(&[SIGINT, SIGTERM])?;
+    let handle = signals.handle();
+    let mut signals = signals.fuse();
+
+    tokio::spawn(async move {
+        while let Some(signal) = signals.next().await {
+            match signal {
+                SIGINT => println!("SIGINT"),
+                SIGTERM => println!("SIGTERM"),
+                _ => unreachable!(),
+            }
+        }
+    });
+
+    handle.close();
+
+    Ok(())
+}
diff --git a/chapter12/src/main.rs b/chapter12/src/main.rs
deleted file mode 100644
index e7a11a9..0000000
--- a/chapter12/src/main.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-fn main() {
-    println!("Hello, world!");
-}