diff --git a/src/zipcrypto.rs b/src/zipcrypto.rs
index 7ad8ddcb..2e97a647 100644
--- a/src/zipcrypto.rs
+++ b/src/zipcrypto.rs
@@ -9,6 +9,7 @@ use std::hash::{Hash, Hasher};
 use std::num::Wrapping;
 
 /// A container to hold the current key state
+#[cfg_attr(fuzzing, derive(arbitrary::Arbitrary))]
 #[derive(Clone, Copy, Hash, Ord, PartialOrd, Eq, PartialEq)]
 pub(crate) struct ZipCryptoKeys {
     key_0: Wrapping<u32>,