diff --git a/crates/misc/run-examples/build.rs b/crates/misc/run-examples/build.rs
index 81caa36d69..a2c6171e4a 100644
--- a/crates/misc/run-examples/build.rs
+++ b/crates/misc/run-examples/build.rs
@@ -3,4 +3,5 @@ fn main() {
         "cargo:rustc-env=TARGET={}",
         std::env::var("TARGET").unwrap()
     );
+    println!("cargo:rerun-if-changed=build.rs");
 }
diff --git a/crates/wasi-common/build.rs b/crates/wasi-common/build.rs
index 236c48d19d..275d8dd6de 100644
--- a/crates/wasi-common/build.rs
+++ b/crates/wasi-common/build.rs
@@ -7,4 +7,6 @@ fn main() {
     println!("cargo:wasi={}", wasi.display());
     // and available to our own crate as WASI_ROOT:
     println!("cargo:rustc-env=WASI_ROOT={}", wasi.display());
+    // and this build.rs script doesn't depend on any files.
+    println!("cargo:rerun-if-changed=build.rs");
 }