diff --git a/crates/fiber/build.rs b/crates/fiber/build.rs
index 9e7b8b5a39..6bfc5c4b9d 100644
--- a/crates/fiber/build.rs
+++ b/crates/fiber/build.rs
@@ -5,13 +5,16 @@ fn main() {
     let arch = env::var("CARGO_CFG_TARGET_ARCH").unwrap();
     let os = env::var("CARGO_CFG_TARGET_OS").unwrap();
     if os == "windows" {
+        println!("cargo:rerun-if-changed=src/windows.c");
         build.file("src/windows.c");
     } else if arch == "s390x" {
+        println!("cargo:rerun-if-changed=src/unix/s390x.S");
         build.file("src/unix/s390x.S");
     } else {
         // assume that this is included via inline assembly in the crate itself,
         // and the crate will otherwise have a `compile_error!` for unsupported
         // platforms.
+        println!("cargo:rerun-if-changed=build.rs");
         return;
     }
     build.define(&format!("CFG_TARGET_OS_{}", os), None);