diff --git a/interp/grid/__init__.py b/interp/grid/__init__.py
index 75bc51c..6761d28 100644
--- a/interp/grid/__init__.py
+++ b/interp/grid/__init__.py
@@ -152,7 +152,8 @@ class grid(object):
     r  = '%d\n' % len(self.verts[0])
     r += '%d\n' % len(self.verts)
     for p in self.verts:
-      r += "%f %f %f\n" % tuple(p)
+      # r += "%f %f %f\n" % tuple(p)
+      r += "%s\n" % " ".join("%f" % i for i in p)
     return r
 
   def __str__(self):