diff --git a/examples/expr.g b/examples/expr.g
index ae807b7..723ab05 100644
--- a/examples/expr.g
+++ b/examples/expr.g
@@ -17,5 +17,5 @@ parser Calculator:
                        )*                 {{ return v }}
 
     # A term is either a number or an expression surrounded by parentheses
-    rule term:           NUM              {{ return atoi(NUM) }}
+    rule term:           NUM              {{ return int(NUM) }}
                        | "\\(" expr "\\)" {{ return expr }}
diff --git a/yapps/cli_tool.py b/yapps/cli_tool.py
index 270207c..692d3b8 100755
--- a/yapps/cli_tool.py
+++ b/yapps/cli_tool.py
@@ -12,6 +12,12 @@
 #
 
 import os, sys, re, types
+#from six import string_types
+PY2 = sys.version_info[0] == 2
+if PY2:
+	string_types = (basestring,)
+else:
+	string_types = (str,)
 
 try: from yapps import runtime, parsetree, grammar
 except ImportError:
@@ -27,7 +33,7 @@ def generate(inputfile, outputfile=None, dump=0, **flags):
     and an output filename (defaulting to X.py)."""
 
     inputfilename = inputfile if isinstance(
-        inputfile, types.StringTypes ) else inputfile.name
+        inputfile, string_types ) else inputfile.name
     if not outputfile:
         if inputfilename.endswith('.g'):
             outputfile = inputfilename[:-2] + '.py'
@@ -38,7 +44,7 @@ def generate(inputfile, outputfile=None, dump=0, **flags):
     preparser, postparser = None, None # Code before and after the parser desc
 
     # Read the entire file
-    if isinstance(inputfile, types.StringTypes):
+    if isinstance(inputfile, string_types):
         inputfile = open(inputfilename)
     s = inputfile.read()
 
@@ -67,7 +73,7 @@ def generate(inputfile, outputfile=None, dump=0, **flags):
     if dump:
         t.dump_information()
     else:
-        if isinstance(outputfile, types.StringTypes):
+        if isinstance(outputfile, string_types):
             outputfile = open(outputfile, 'w')
         t.output = outputfile
         t.generate_output()
diff --git a/yapps/parsetree.py b/yapps/parsetree.py
index e9c3a16..514d64a 100644
--- a/yapps/parsetree.py
+++ b/yapps/parsetree.py
@@ -272,6 +272,7 @@ class Generator:
         self.calculate()
         self.write(self.preparser)
         self.write("# Begin -- grammar generated by Yapps\n")
+        self.write("from __future__ import print_function\n")
         self.write("import sys, re\n")
         self.write("from yapps import runtime\n")
         self.write("\n")
@@ -313,7 +314,7 @@ class Generator:
             self.write(INDENT*3, "f = open(argv[2],'r')\n")
             self.write(INDENT*2, "else:\n")
             self.write(INDENT*3, "f = stdin\n")
-            self.write(INDENT*2, "print parse(argv[1], f.read())\n")
+            self.write(INDENT*2, "print(parse(argv[1], f.read()))\n")
             self.write(INDENT, "else: print ('Args:  <rule> [<filename>]', file=sys.stderr)\n")
             self.write("# End -- grammar generated by Yapps\n")