diff --git a/russh/Cargo.toml b/russh/Cargo.toml
index 7a0a78d0..73080582 100644
--- a/russh/Cargo.toml
+++ b/russh/Cargo.toml
@@ -120,3 +120,8 @@ tempfile = "3.14.0"
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
 russh-sftp = "2.0.5"
 tokio.workspace = true
+
+[[example]]
+name = "sftp_server"
+path = "examples/sftp_server.rs"
+required-features = ["async-trait"]
diff --git a/russh/src/auth.rs b/russh/src/auth.rs
index 62ad4029..018d740c 100644
--- a/russh/src/auth.rs
+++ b/russh/src/auth.rs
@@ -173,15 +173,17 @@ impl<R: AsyncRead + AsyncWrite + Unpin + Send + 'static> Signer
 {
     type Error = AgentAuthError;
 
-    async fn auth_publickey_sign(
+    fn auth_publickey_sign(
         &mut self,
         key: &ssh_key::PublicKey,
         hash_alg: Option<HashAlg>,
         to_sign: CryptoVec,
-    ) -> Result<CryptoVec, Self::Error> {
-        self.sign_request(key, hash_alg, to_sign)
-            .await
-            .map_err(Into::into)
+    ) -> impl Future<Output = Result<CryptoVec, Self::Error>> {
+        async move {
+            self.sign_request(key, hash_alg, to_sign)
+                .await
+                .map_err(Into::into)
+        }
     }
 }