diff --git a/overviewer.py b/overviewer.py
index 0b0f6fe..7759aa2 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -400,9 +400,9 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
         else:
             tex = texcache[texopts_key]
 
-        rset = w.get_regionset(render['dimension'])
+        rset = w.get_regionset(render['dimension'][1])
         if rset == None: # indicates no such dimension was found:
-            logging.error("Sorry, you requested dimension '%s' for %s, but I couldn't find it", render['dimension'], render_name)
+            logging.error("Sorry, you requested dimension '%s' for %s, but I couldn't find it", render['dimension'][0], render_name)
             return 1
 
         #################
diff --git a/overviewer_core/aux_files/genPOI.py b/overviewer_core/aux_files/genPOI.py
index 80439cb..61bae09 100755
--- a/overviewer_core/aux_files/genPOI.py
+++ b/overviewer_core/aux_files/genPOI.py
@@ -57,10 +57,9 @@ def handlePlayers(rset, render, worldpath):
     # only handle this region set once
     if 'Players' in rset._pois:
         return
-    dimension = {'overworld': 0,
-                 'nether': -1,
-                 'end': 1,
-                 'default': 0}[render['dimension']]
+    dimension = {None: 0,
+                 'DIM-1': -1,
+                 'DIM1': 1}[rset.get_type()]
     playerdir = os.path.join(worldpath, "players")
     if os.path.isdir(playerdir):
         playerfiles = os.listdir(playerdir)
@@ -165,9 +164,9 @@ def main():
         else:
             w = worldcache[render['world']]
         
-        rset = w.get_regionset(render['dimension'])
+        rset = w.get_regionset(render['dimension'][1])
         if rset == None: # indicates no such dimension was found:
-            logging.error("Sorry, you requested dimension '%s' for %s, but I couldn't find it", render['dimension'], render_name)
+            logging.error("Sorry, you requested dimension '%s' for %s, but I couldn't find it", render['dimension'][0], render_name)
             return 1
       
         for f in render['markers']:
diff --git a/overviewer_core/settingsValidators.py b/overviewer_core/settingsValidators.py
index 6476bb6..72e975c 100644
--- a/overviewer_core/settingsValidators.py
+++ b/overviewer_core/settingsValidators.py
@@ -182,6 +182,8 @@ def validateStr(s):
     return str(s)
 
 def validateDimension(d):
+    # returns (original, argument to get_type)
+    
     # these are provided as arguments to RegionSet.get_type()
     pretty_names = {
         "nether": "DIM-1",
@@ -191,12 +193,9 @@ def validateDimension(d):
     }
     
     try:
-        return pretty_names[d]
+        return (d, pretty_names[d])
     except KeyError:
-        if d.startswith("DIM"):
-            return d
-    
-    raise ValidationException("%r is not a valid dimension" % d)
+        return (d, d)
 
 def validateOutputDir(d):
     _, d = checkBadEscape(d)
diff --git a/overviewer_core/tileset.py b/overviewer_core/tileset.py
index e3416ff..db05a50 100644
--- a/overviewer_core/tileset.py
+++ b/overviewer_core/tileset.py
@@ -524,7 +524,7 @@ class TileSet(object):
                 base = self.options.get('base'),
                 bgcolor = bgcolorformat(self.options.get('bgcolor')),
                 world = self.options.get('worldname_orig') +
-                    (" - " + self.options.get('dimension') if self.options.get('dimension') != 'default' else ''),
+                    (" - " + self.options.get('dimension')[0] if self.options.get('dimension')[1] != 0 else ''),
                 last_rendertime = self.max_chunk_mtime,
                 imgextension = self.imgextension,
                 isOverlay = isOverlay,