diff --git a/Cargo.toml b/Cargo.toml
index e2d1461..ae4e1d7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -57,6 +57,7 @@ expectrl = "0.6.0"
 trussed-usbip = { git = "https://github.com/trussed-dev/pc-usbip-runner", default-features = false, features = ["ccid"], rev = "f3a680ca4c9a1411838ae0774f1713f79d4c2979"}
 usbd-ccid = { version = "0.2.0", features = ["highspeed-usb"]}
 rand = "0.8.5"
+asn1 = "0.15.2"
 
 [features]
 default = []
diff --git a/src/lib.rs b/src/lib.rs
index 28e1507..779ddbd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -685,7 +685,7 @@ impl<'a, T: Client> LoadedAuthenticator<'a, T> {
             alg.sign_mechanism(),
             id,
             message,
-            trussed::types::SignatureSerialization::Raw,
+            alg.sign_serialization(),
         ))
         .signature;
         reply.expand(&[0x7C])?;
diff --git a/src/piv_types.rs b/src/piv_types.rs
index 595abe1..aa6e636 100644
--- a/src/piv_types.rs
+++ b/src/piv_types.rs
@@ -6,7 +6,7 @@ use core::convert::{TryFrom, TryInto};
 use flexiber::Encodable;
 use hex_literal::hex;
 use serde::{Deserialize, Serialize};
-use trussed::types::Mechanism;
+use trussed::types::{Mechanism, SignatureSerialization};
 
 #[macro_export]
 macro_rules! enum_u8 {
@@ -171,6 +171,13 @@ impl AsymmetricAlgorithms {
         }
     }
 
+    pub fn sign_serialization(self) -> SignatureSerialization {
+        match self {
+            Self::Rsa2048 | Self::Rsa4096 => SignatureSerialization::Raw,
+            Self::P256 => SignatureSerialization::Asn1Der,
+        }
+    }
+
     pub fn is_rsa(self) -> bool {
         use AsymmetricAlgorithms::*;
         matches!(self, Rsa2048 | Rsa4096)
diff --git a/tests/pivy.rs b/tests/pivy.rs
index f81a9e5..ea9b15b 100644
--- a/tests/pivy.rs
+++ b/tests/pivy.rs
@@ -86,6 +86,65 @@ fn ecdh() {
     with_vsc(WITHOUT_UUID, test);
 }
 
+#[test_log::test]
+fn sign() {
+    let test_rsa = || {
+        let mut p = spawn(&format!("pivy-tool -A 3des -K 010203040506070801020304050607080102030405060708 generate 9A -a rsa2048 -P 123456")).unwrap();
+        p.expect(Regex("ssh-rsa (?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)? PIV_slot_9A@[A-F0-9]{20}")).unwrap();
+        p.expect(Eof).unwrap();
+        assert_eq!(p.wait().unwrap(), WaitStatus::Exited(p.pid(), 0));
+
+        let mut p = Command::new("pivy-tool")
+            .args(["sign", "9A", "-P", "123456"])
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .spawn()
+            .unwrap();
+        let mut stdin = p.stdin.take().unwrap();
+        write!(stdin, "data").unwrap();
+        drop(stdin);
+
+        assert_eq!(p.wait().unwrap().code(), Some(0));
+    };
+
+    let test_p256 = || {
+        let mut p = spawn(&format!("pivy-tool -A 3des -K 010203040506070801020304050607080102030405060708 generate 9A -a eccp256 -P 123456")).unwrap();
+        p.expect(Regex("ecdsa-sha2-nistp256 (?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)? PIV_slot_9A@[A-F0-9]{20}")).unwrap();
+        p.expect(Eof).unwrap();
+        assert_eq!(p.wait().unwrap(), WaitStatus::Exited(p.pid(), 0));
+
+        let mut p = Command::new("pivy-tool")
+            .args(["sign", "9A", "-P", "123456"])
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            .spawn()
+            .unwrap();
+        let mut stdin = p.stdin.take().unwrap();
+        let mut stdout = p.stdout.take().unwrap();
+        write!(stdin, "data").unwrap();
+        drop(stdin);
+
+        let mut out = Vec::new();
+        stdout.read_to_end(&mut out).unwrap();
+        // Check that the signature is an asn.1 sequence
+        let res: asn1::ParseResult<_> = asn1::parse(&out, |d| {
+            return d.read_element::<asn1::Sequence>()?.parse(|d| {
+                d.read_element::<asn1::BigUint>()?;
+                d.read_element::<asn1::BigUint>()?;
+                return Ok(());
+            });
+        });
+        res.unwrap();
+
+        assert_eq!(p.wait().unwrap().code(), Some(0));
+    };
+
+    let test = || (test_rsa(), test_p256());
+
+    with_vsc(WITH_UUID, test);
+    with_vsc(WITHOUT_UUID, test);
+}
+
 const LARGE_CERT: &str = "-----BEGIN CERTIFICATE-----
 MIIHNTCCBh2gAwIBAgIUBeJLVUnOULY3fhLvjaWOZe/qWfYwDQYJKoZIhvcNAQEL
 BQAwggIoMQswCQYDVQQGEwJURTGBizCBiAYDVQQIDIGAVEVTVFRFU1RURVNUVEVT