diff --git a/deluge/core/core.py b/deluge/core/core.py
index 1ca6f92d8..a73bb6485 100644
--- a/deluge/core/core.py
+++ b/deluge/core/core.py
@@ -134,8 +134,11 @@ class Core(component.Component):
         # store the one in the config so we can restore it on shutdown
         self.__old_interface = None
         if listen_interface:
-            self.__old_interface = self.config["listen_interface"]
-            self.config["listen_interface"] = listen_interface
+            if deluge.common.is_ip(listen_interface):
+                self.__old_interface = self.config["listen_interface"]
+                self.config["listen_interface"] = listen_interface
+            else:
+                log.error("Invalid listen interface (must be IP Address): %s", listen_interface)
 
     def start(self):
         """Starts the core"""
diff --git a/deluge/ui/gtkui/preferences.py b/deluge/ui/gtkui/preferences.py
index 52feb5555..149208de1 100644
--- a/deluge/ui/gtkui/preferences.py
+++ b/deluge/ui/gtkui/preferences.py
@@ -586,7 +586,9 @@ class Preferences(component.Component):
         new_core_config["outgoing_ports"] = outgoing_ports
         new_core_config["random_outgoing_ports"] = \
             self.glade.get_widget("chk_random_outgoing_ports").get_active()
-        new_core_config["listen_interface"] = self.glade.get_widget("entry_interface").get_text()
+        incoming_address = self.glade.get_widget("entry_interface").get_text().strip()
+        if deluge.common.is_ip(incoming_address) or not incoming_address:
+            new_core_config["listen_interface"] = incoming_address
         new_core_config["peer_tos"] = self.glade.get_widget("entry_peer_tos").get_text()
         new_core_config["dht"] = self.glade.get_widget("chk_dht").get_active()
         new_core_config["upnp"] = self.glade.get_widget("chk_upnp").get_active()