diff --git a/build.rs b/build.rs
new file mode 100644
index 00000000..dc9c06dd
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,4 @@
+fn main() {
+    // Rebuild program if any file in commands directory changes.
+    println!("cargo:rerun-if-changed=src/commands");
+}