diff --git a/cmd/tlsdiag/client.go b/cmd/tlsdiag/client.go
index 8b0fc46..9bf2e69 100644
--- a/cmd/tlsdiag/client.go
+++ b/cmd/tlsdiag/client.go
@@ -23,7 +23,7 @@ func StartClient() error {
 		return err
 	}
 
-	peerID, err := peer.IDB58Decode(*peerIDString)
+	peerID, err := peer.Decode(*peerIDString)
 	if err != nil {
 		return err
 	}