diff --git a/src/assert.rs b/src/assert.rs
index 027787c..b4f08a8 100644
--- a/src/assert.rs
+++ b/src/assert.rs
@@ -295,13 +295,13 @@ impl AssertionRef {
         }
     }
 
-    pub fn verify(&self, idx: usize, alg: CoseAlg, pubkey: PubKey) -> Result<()> {
+    pub fn verify(&self, idx: usize, pubkey: PubKey) -> Result<()> {
         assert!(idx < self.count());
         unsafe {
             check(fido_assert_verify(
                 self.as_ptr(),
                 idx,
-                alg as i32,
+                pubkey.alg() as i32,
                 pubkey.as_ptr(),
             ))
         }
diff --git a/src/pkey.rs b/src/pkey.rs
index d556118..75518b4 100644
--- a/src/pkey.rs
+++ b/src/pkey.rs
@@ -2,6 +2,7 @@ use std::ffi::c_void;
 
 use libfido2_sys::*;
 
+use crate::CoseAlg;
 use crate::error::Result;
 use crate::util::check_initialized;
 
@@ -94,4 +95,13 @@ impl PubKey {
             PubKey::Rsa256PubKey(pk) => pk.as_ptr() as *const c_void,
         }
     }
+
+    pub(crate) fn alg(&self) -> CoseAlg {
+        match self {
+            PubKey::Ec25519(_) => CoseAlg::Ed25519,
+            PubKey::Ecdsa256(_) => CoseAlg::Ecdsa256,
+            PubKey::Ecdsa384(_) => CoseAlg::Ecdsa384,
+            PubKey::Rsa256PubKey(_) => CoseAlg::Rsa,
+        }
+    }
 }