diff --git a/erynrl/ai.py b/erynrl/ai.py
index ade0b33..f7a30c1 100644
--- a/erynrl/ai.py
+++ b/erynrl/ai.py
@@ -77,7 +77,10 @@ class HostileEnemy(AI):
                     directions.remove(direction)
                     new_position = self.entity.position + direction
                     overlaps_existing_entity = any(new_position == ent.position for ent in engine.entities)
-                    tile_is_walkable = engine.map.tile_is_walkable(new_position)
+                    try:
+                        tile_is_walkable = engine.map.tile_is_walkable(new_position)
+                    except ValueError:
+                        tile_is_walkable = False
                     if not overlaps_existing_entity and tile_is_walkable:
                         if engine.map.visible[tuple(self.entity.position)]:
                             log.AI.info('Hero is NOT visible to %s, bumping %s randomly', self.entity, direction)