diff --git a/dsa/src/signing_key.rs b/dsa/src/signing_key.rs
index 1204806e..e52e3281 100644
--- a/dsa/src/signing_key.rs
+++ b/dsa/src/signing_key.rs
@@ -22,7 +22,7 @@ use signature::{
     rand_core::CryptoRngCore,
     DigestSigner, RandomizedDigestSigner, Signer,
 };
-use zeroize::{Zeroize, Zeroizing};
+use zeroize::{Zeroize, ZeroizeOnDrop, Zeroizing};
 
 /// DSA private key.
 ///
@@ -114,6 +114,8 @@ impl SigningKey {
     }
 }
 
+impl ZeroizeOnDrop for SigningKey {}
+
 impl Signer<Signature> for SigningKey {
     fn try_sign(&self, msg: &[u8]) -> Result<Signature, signature::Error> {
         let digest = sha2::Sha256::new_with_prefix(msg);