diff --git a/raiden/app.py b/raiden/app.py
index 3dcdb63624..0fa81c2b41 100644
--- a/raiden/app.py
+++ b/raiden/app.py
@@ -80,9 +80,12 @@ def __init__(self, config, chain, default_registry, discovery, transport_class=U
                 config,
             )
         except filelock.Timeout:
-            pubkey = privatekey_to_address(unhexlify(self.config['privatekey_hex']))
-            print('FATAL: Another Raiden instance already running for account 0x%s' %
-                  hexlify(str(pubkey)))
+            pubkey = hexlify(
+                privatekey_to_address(unhexlify(self.config['privatekey_hex']))).decode()
+            print(
+                f'FATAL: Another Raiden instance already running for account 0x{pubkey} on '
+                f'network id {chain.network_id}'
+            )
             sys.exit(1)
         self.start_console = self.config['console']