diff --git a/openpgp-card/src/card_app.rs b/openpgp-card/src/card_app.rs
index 08e05ce..5d7b34f 100644
--- a/openpgp-card/src/card_app.rs
+++ b/openpgp-card/src/card_app.rs
@@ -554,7 +554,9 @@ impl CardApp {
         let data = match algo {
             Algo::Rsa(rsa) => Self::rsa_algo_attrs(rsa)?,
             Algo::Ecc(ecc) => Self::ecc_algo_attrs(ecc.oid(), ecc.ecc_type()),
-            _ => unimplemented!(),
+            _ => {
+                return Err(anyhow!("Unexpected Algo {:?}", algo).into());
+            }
         };
 
         // Command to PUT the algorithm attributes
diff --git a/openpgp-card/src/keys.rs b/openpgp-card/src/keys.rs
index 4481815..11bfb7c 100644
--- a/openpgp-card/src/keys.rs
+++ b/openpgp-card/src/keys.rs
@@ -88,9 +88,11 @@ fn tlv_to_pubkey(tlv: &Tlv, algo: &Algo) -> Result<PublicKeyMaterial> {
             Ok(PublicKeyMaterial::E(ecc))
         }
 
-        (_, _, _) => {
-            unimplemented!()
-        }
+        (_, _, _) => Err(anyhow!(
+            "Unexpected public key material from card {:?}",
+            tlv
+        )
+        .into()),
     }
 }