diff --git a/libafl/Cargo.toml b/libafl/Cargo.toml
index 3c820ec845..8d762a6d63 100644
--- a/libafl/Cargo.toml
+++ b/libafl/Cargo.toml
@@ -75,6 +75,7 @@ wait-timeout = { version = "0.2", optional = true } # used by CommandExecutor to
 z3 = { version = "0.11", features = ["static-link-z3"], optional = true } # for concolic mutation
 
 # AGPL
+# !!! this create requires nightly
 grammartec = { version = "0.1", optional = true }
 
 [target.'cfg(unix)'.dependencies]
diff --git a/libafl/build.rs b/libafl/build.rs
index e9d3f5d9e9..f75be9ddb9 100644
--- a/libafl/build.rs
+++ b/libafl/build.rs
@@ -1,7 +1,13 @@
 #[rustversion::nightly]
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rustc-cfg=unstable_feature");
 }
 
 #[rustversion::not(nightly)]
-fn main() {}
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+    if cfg!(feature = "nautilus") {
+        panic!("The 'nautilus' feature of libafl requires a nightly compiler");
+    }
+}