diff --git a/ambient.py b/ambient.py
index 90884de..2566c55 100644
--- a/ambient.py
+++ b/ambient.py
@@ -52,7 +52,7 @@ def send(self, data, timeout = 30.0):
     def read(self, **args):
         url = self.url + '/data'
         __o = []
-        if hasattr(self, 'readKey'):
+        if self.readKey is not None:
             __o.append('readKey=' + self.readKey)
         if 'date' in args:
             __o.append('date=' + args['date'])
@@ -78,7 +78,7 @@ def read(self, **args):
 
     def getprop(self, **args):
         url = self.url
-        if hasattr(self, 'readKey'):
+        if self.readKey is not None:
             url = url + '?' + 'readKey=' + self.readKey
         timeout = 30.0
         if 'timeout' in args: