diff --git a/Lib/mhlib.py b/Lib/mhlib.py
index feb554e..e5900ac 100644
--- a/Lib/mhlib.py
+++ b/Lib/mhlib.py
@@ -788,7 +788,7 @@
         self.pairs = []
         self.sep = sep
         self.rng = rng
-        if data is not None: self.fromstring(data)
+        if data: self.fromstring(data)
 
     def reset(self):
         self.pairs = []