diff --git a/csv2json.py b/csv2json.py
index f1073cd..a833c88 100755
--- a/csv2json.py
+++ b/csv2json.py
@@ -3,9 +3,18 @@
 A simple script for generating JSON/JavaScript from comma-separated (or
 otherwise delimited) values.
 
+Python 2.7 or higher is recommended see :
+"Floating Point Arithmetic issues and Limitations" at
+http://docs.python.org/2/tutorial/floatingpoint.html
+
 by Shawn Allen <shawn at stamen dot com>
+modified by Alexandre Dube <adube at mapgears dot com> for lighter json
 """
-import csv, simplejson
+import csv
+try:
+    import json
+except ImportError:
+    import simplejson as json
 from StringIO import StringIO
 
 # These are shorthands for delimiters that might be a pain to type or escape.
@@ -13,24 +22,44 @@
                  'sc':  ';',
                  'bar': '|'}
 
+def is_number(s):
+    try:
+        float(s)
+        return True
+    except ValueError:
+        return False
+
+def is_int(s):
+    try:
+        int(s)
+        return True
+    except ValueError:
+        return False
+
 def csv2json(csv_file, delimiter=',', quotechar='"', indent=None, callback=None, variable=None, **csv_opts):
     if delimiter_map.has_key(delimiter):
         delimiter = delimiter_map.get(delimiter)
     reader = csv.DictReader(csv_file, delimiter=delimiter, quotechar=quotechar or None, **csv_opts)
-    rows = [row for row in reader]
+
+    # manually cast to integer or float according values for a lighter json
+    # csv.DictReader has no mean to return unquoted integer and float values,
+    # that's why it's manually done here. None really efficient upon script
+    # execution, but json is much lighter that way
+    rows = []
+    for row in reader:
+        for field in row:
+            if is_number(row[field]):
+                if is_int(row[field]):
+                    row[field] = int(row[field])
+                else:
+                    row[field] = float(row[field])
+        rows.append(row)
+
     if hasattr(indent, 'isdigit') and indent.isdigit():
         indent = ' ' * int(indent)
-    out = StringIO()
-    if callback:
-        out.write('%s(' % callback);
-    elif variable:
-        out.write('var %s = ' % variable)
-    simplejson.dump(rows, out, indent=indent)
-    if callback:
-        out.write(');');
-    elif variable:
-        out.write(';')
-    return out.getvalue()
+
+    return json.dumps(rows, indent=indent, separators=(',', ':'),
+                      ensure_ascii=False)
 
 if __name__ == '__main__':
     import sys