diff --git a/README.md b/README.md
index 185a0c7..43cdd2d 100644
--- a/README.md
+++ b/README.md
@@ -36,9 +36,16 @@ Add a `build.rs` file to your project to compile the protos and generate Rust co
 
 ```rust
 fn main() {
+    let proto_source_files = ["./service.proto"];
+    
+    // Tell Cargo to rerun this build script if any of the proto files change
+    for entry in &proto_source_files {
+        println!("cargo:rerun-if-changed={}", entry);
+    }
+
     prost_build::Config::new()
         .service_generator(twirp_build::service_generator())
-        .compile_protos(&["./service.proto"], &["./"])
+        .compile_protos(&proto_source_files, &["./"])
         .expect("error compiling protos");
 }
 ```