diff --git a/tools/python/pizza/dump.py b/tools/python/pizza/dump.py
index 76e1f3bceed9ee428973113c6d69f72a7f2d308e..9f59f2793303883195cb7712dccca4d1180a0a86 100644
--- a/tools/python/pizza/dump.py
+++ b/tools/python/pizza/dump.py
@@ -453,6 +453,7 @@ class dump:
   # --------------------------------------------------------------------
 
   def scale_one(self,snap,x,y,z):
+    if snap.atoms == None: return
     xprdinv = 1.0 / (snap.xhi - snap.xlo)
     yprdinv = 1.0 / (snap.yhi - snap.ylo)
     zprdinv = 1.0 / (snap.zhi - snap.zlo)
@@ -481,6 +482,7 @@ class dump:
   # --------------------------------------------------------------------
 
   def unscale_one(self,snap,x,y,z):
+    if snap.atoms == None: return
     xprd = snap.xhi - snap.xlo
     yprd = snap.yhi - snap.ylo
     zprd = snap.zhi - snap.zlo