diff --git a/odi6/odi6.py b/odi6/odi6.py
index f754170..8ea17a1 100755
--- a/odi6/odi6.py
+++ b/odi6/odi6.py
@@ -145,7 +145,7 @@ same target, doing nothing."""
                 f"/domain/zone/{self.config['domain']}/record",
                 **params,
             )
-        self._log.debug(f"Result: {result}")
+        self._log.debug("Result: %s", result)
 
     def _determine_ip(self):
         ipv6 = None
@@ -165,8 +165,14 @@ same target, doing nothing."""
                 return ipv4, ipv6
             except ValueError as error:
                 self._log.error(
-                    f"""'{self.config['network_interface']}' is NOT a
-valid network interface. {error}"""
+                    "'%s' is NOT a valid network interface. %s",
+                    self.config['network_interface'],
+                    error
+                )
+            except KeyError:
+                self._log.error(
+                    "Not enough interfaces?. %s",
+                    iface
                 )
         elif self.config['ip_method'] == 'web':
             s = requests.Session()