diff --git a/crypto/bip32.c b/crypto/bip32.c
index f1eb47736..f7fb92046 100644
--- a/crypto/bip32.c
+++ b/crypto/bip32.c
@@ -765,17 +765,21 @@ int hdnode_sign(HDNode *node, const uint8_t *msg, uint32_t msg_len,
   } else if (node->curve == &curve25519_info) {
     return 1;  // signatures are not supported
   } else {
-    hdnode_fill_public_key(node);
     if (node->curve == &ed25519_info) {
+      hdnode_fill_public_key(node);
       ed25519_sign(msg, msg_len, node->private_key, node->public_key + 1, sig);
     } else if (node->curve == &ed25519_sha3_info) {
+      hdnode_fill_public_key(node);
       ed25519_sign_sha3(msg, msg_len, node->private_key, node->public_key + 1,
                         sig);
 #if USE_KECCAK
     } else if (node->curve == &ed25519_keccak_info) {
+      hdnode_fill_public_key(node);
       ed25519_sign_keccak(msg, msg_len, node->private_key, node->public_key + 1,
                           sig);
 #endif
+    } else {
+      return 1;  // unknown or unsupported curve
     }
     return 0;
   }