diff --git a/uncompyle6/main.py b/uncompyle6/main.py
index 60572c04..8d662cf7 100644
--- a/uncompyle6/main.py
+++ b/uncompyle6/main.py
@@ -29,7 +29,7 @@ def uncompyle(version, co, out=None, showasm=False, showast=False,
     try:
         pysource.deparse_code(version, co, out, showasm, showast, showgrammar,
                               code_objects=code_objects)
-    except pysource.WalkerError as e:
+    except pysource.SourceWalkerError as e:
         # deparsing failed
         if real_out != out:
             print(e, file=real_out)
diff --git a/uncompyle6/semantics/fragments.py b/uncompyle6/semantics/fragments.py
index 1bd91d0e..e413f2bd 100644
--- a/uncompyle6/semantics/fragments.py
+++ b/uncompyle6/semantics/fragments.py
@@ -67,7 +67,7 @@ TABLE_DIRECT_FRAGMENT = {
     #     '%|for %c%x in %c:\n%+%c%-%|else:\n%+%c%-\n\n', 3, (3, (2,)), 1, 4, -2),
     }
 
-class Traverser(pysource.Walker, object):
+class FragmentsWalker(pysource.SourceWalker, object):
     stacked_params = ('f', 'indent', 'isLambda', '_globals')
 
     def __init__(self, version, scanner, showast=False,
@@ -1260,8 +1260,8 @@ def deparse_code(version, co, out=StringIO(), showasm=False, showast=False,
     debug_parser['reduce'] = showgrammar
 
     #  Build AST from disassembly.
-    # deparsed = pysource.Walker(out, scanner, showast=showast)
-    deparsed = Traverser(version, scanner, showast=showast, debug_parser=debug_parser)
+    # deparsed = pysource.FragmentsWalker(out, scanner, showast=showast)
+    deparsed = FragmentsWalker(version, scanner, showast=showast, debug_parser=debug_parser)
 
     deparsed.ast = deparsed.build_ast(tokens, customize)
 
@@ -1336,5 +1336,5 @@ if __name__ == '__main__':
     # check_args(['3', '5'])
     deparse_test(get_code_for_fn(gcd))
     # deparse_test(get_code_for_fn(gcd))
-    # deparse_test(get_code_for_fn(Traverser.fixup_offsets))
+    # deparse_test(get_code_for_fn(FragmentsWalker.fixup_offsets))
     # deparse_test(inspect.currentframe().f_code)
diff --git a/uncompyle6/semantics/pysource.py b/uncompyle6/semantics/pysource.py
index 634c180f..3dfdac38 100644
--- a/uncompyle6/semantics/pysource.py
+++ b/uncompyle6/semantics/pysource.py
@@ -472,14 +472,14 @@ def find_none(node):
             return True
     return False
 
-class WalkerError(Exception):
+class SourceWalkerError(Exception):
     def __init__(self, errmsg):
         self.errmsg = errmsg
 
     def __str__(self):
         return self.errmsg
 
-class Walker(GenericASTTraversal, object):
+class SourceWalker(GenericASTTraversal, object):
     stacked_params = ('f', 'indent', 'isLambda', '_globals')
 
     def __init__(self, version, out, scanner, showast=False,
@@ -1632,7 +1632,7 @@ def deparse_code(version, co, out=sys.stdout, showasm=False, showast=False,
     debug_parser['reduce'] = showgrammar
 
     #  Build AST from disassembly.
-    deparsed = Walker(version, out, scanner, showast=showast, debug_parser=debug_parser)
+    deparsed = SourceWalker(version, out, scanner, showast=showast, debug_parser=debug_parser)
 
     deparsed.ast = deparsed.build_ast(tokens, customize)
 
@@ -1660,7 +1660,7 @@ def deparse_code(version, co, out=sys.stdout, showasm=False, showast=False,
         deparsed.write('# global %s ## Warning: Unused global' % g)
 
     if deparsed.ERROR:
-        raise WalkerError("Deparsing stopped due to parse error")
+        raise SourceWalkerError("Deparsing stopped due to parse error")
     return deparsed
 
 if __name__ == '__main__':