diff --git a/src/lib.rs b/src/lib.rs
index 052452f9..fd3630da 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -57,7 +57,7 @@ pub fn exit_qemu(exit_code: QemuExitCode) {
 
 /// Entry point for `cargo xtest`
 #[cfg(test)]
-#[no_mangle]
+#[unsafe(no_mangle)]
 pub extern "C" fn _start() -> ! {
     test_main();
     loop {}