diff --git a/README.rst b/README.rst
index 542f2c4..dd77116 100644
--- a/README.rst
+++ b/README.rst
@@ -123,7 +123,7 @@ Running
 -------
 To generate a set of Google Map tiles, use the gmap.py script like this::
 
-    python gmap.py [OPTIONS] <World Number / Path to World> <Output Directory>
+    python gmap.py [OPTIONS] <World # / Name / Path to World> <Output Directory>
 
 The output directory will be created if it doesn't exist. This will generate a
 set of image tiles for your world in the directory you choose. When it's done,
diff --git a/gmap.py b/gmap.py
index 51d97bc..9a8cd52 100755
--- a/gmap.py
+++ b/gmap.py
@@ -36,8 +36,8 @@ import world
 import quadtree
 
 helptext = """
-%prog [OPTIONS] <World # / Path to World> <tiles dest dir>
-%prog -d <World # / Path to World / Path to cache dir> [tiles dest dir]"""
+%prog [OPTIONS] <World # / Name / Path to World> <tiles dest dir>
+%prog -d <World # / Name / Path to World / Path to cache dir> [tiles dest dir]"""
 
 def main():
     try:
@@ -69,11 +69,21 @@ def main():
     worlddir = args[0]
 
     if not os.path.exists(worlddir):
+        # world given is either world number, or name
         try:
             worldnum = int(worlddir)
             worlddir = world.get_worlds()[worldnum]['path']
-        except (ValueError, KeyError):
-            print "Invalid world number or directory"
+        except ValueError:
+            # it wasn't a number, try using it as a name
+            worlddir = os.path.join(world.get_save_dir(), worlddir)
+            if not os.path.exists(worlddir):
+                # still doesn't exist! print help and die.
+                print "Invalid world name or path"
+                parser.print_help()
+                sys.exit(1)
+        except KeyError:
+            # it was an invalid number
+            print "Invalid world number"
             parser.print_help()
             sys.exit(1)