diff --git a/src/zipcrypto.rs b/src/zipcrypto.rs
index 71af39e3..a61dd354 100644
--- a/src/zipcrypto.rs
+++ b/src/zipcrypto.rs
@@ -18,10 +18,17 @@ pub(crate) struct ZipCryptoKeys {
 }
 
 impl Debug for ZipCryptoKeys {
+    #[allow(unreachable_code)]
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        let mut t = DefaultHasher::new();
-        self.hash(&mut t);
-        f.write_fmt(format_args!("ZipCryptoKeys(hash {})", t.finish()))
+        #[cfg(not(any(test,fuzzing)))]
+        {
+            let mut t = DefaultHasher::new();
+            self.hash(&mut t);
+            return f.write_fmt(format_args!("ZipCryptoKeys(hash {})", t.finish()));
+        }
+        #[cfg(any(test,fuzzing))]
+        return f.write_fmt(format_args!("ZipCryptoKeys({:#10x},{:#10x},{:#10x})",
+                                        self.key_0, self.key_1, self.key_2));
     }
 }