diff --git a/src/lattice.py b/src/lattice.py
index 4a15892..fbe5bb7 100644
--- a/src/lattice.py
+++ b/src/lattice.py
@@ -24,18 +24,18 @@ class Lattice():
         specs=spec.split(":")
         # check type of lattice
         if specs[0]=="square":
-            return Square_lattice.new_square(specs[1:],spec)
+            return Lattice_square.new_square(specs[1:],spec)
         else:
             return(None,"error: unrecognized lattice type: '"+specs[0]+"'")
 
 
 # square lattice
-class Square_lattice(Lattice):
+class Lattice_square(Lattice):
     def __init__(self,**kwargs):
 
         self.spacing=kwargs.get("spacing",1.)
 
-        super(Square_lattice,self).__init__(**kwargs,type="square")
+        super(Lattice_square,self).__init__(**kwargs,type="square")
 
     # lattice point nearest to point
     def nearest(self,point):
@@ -49,12 +49,12 @@ class Square_lattice(Lattice):
     def new_square(specs,spec):
         # no optional args
         if len(specs)==0:
-            return (Square_lattice(),"")
+            return (Lattice_square(),"")
         if len(specs)>1:
             return (None,"error: '"+spec+"' is not a valid specification for the square lattice: should be 'square[:spacing]'")
         try:
             spacing=float(specs[0])
-            return (Square_lattice(spacing=spacing),"")
+            return (Lattice_square(spacing=spacing),"")
         except:
             return (None,"error: '"+spec+"' is not a valid specification for the square lattice: should be 'square[:spacing]'")
         
diff --git a/src/painter.py b/src/painter.py
index 9055b9a..f11cfe8 100644
--- a/src/painter.py
+++ b/src/painter.py
@@ -7,7 +7,6 @@ from kivy.graphics import Color,Line
 from point import Point
 from polyomino import Cross
 from polyomino import Square_element
-from lattice import Square_lattice
 
 from tools import remove_fromlist