diff --git a/Equation/core.py b/Equation/core.py
index 4574feb..96127a1 100644
--- a/Equation/core.py
+++ b/Equation/core.py
@@ -272,6 +272,8 @@ def __call__(self,*args,**kwargs):
         varies
             Result of evaluating the Expression, type will depende appon the expression and the variables used to evaluate the expression.
         """
+        if len(self.__expr) == 0:
+            return None
         self.variables = {}
         self.variables.update(constants) # i.e. pi, e, i, etc.
         self.variables.update(self.__vars)
diff --git a/tests/test_Equation.py b/tests/test_Equation.py
index fd20bbe..20721e0 100755
--- a/tests/test_Equation.py
+++ b/tests/test_Equation.py
@@ -75,9 +75,9 @@ def testRepr(self):
 
     def testStr(self):
         self.assertEqual(str(self.fn),"")
-        
+
     def testCall(self):
-        self.assertEqual(self.fn(), 0)
+        self.assertEqual(self.fn(), None)
 
     def tearDown(self):
         pass