fix float dumping
diff --git a/pytoml/writer.py b/pytoml/writer.py
index 20cb80c..4e1691e 100644
--- a/pytoml/writer.py
+++ b/pytoml/writer.py
@@ -61,7 +61,7 @@
     if isinstance(v, int) or isinstance(v, long):
         return unicode(v)
     if isinstance(v, float):
-        return '{0:.17f}'.format(v)
+        return repr(v)
     elif isinstance(v, unicode) or isinstance(v, bytes):
         return _escape_string(v)
     elif isinstance(v, datetime.datetime):