diff --git a/demo_code.py b/demo_code.py
index 9fde50644..539fc27db 100644
--- a/demo_code.py
+++ b/demo_code.py
@@ -16,7 +16,7 @@ def __init__(self):
         self.limits = (1, 10)
 
     def get_number(self, min_max):
-        raise NotImplemented
+        raise NotImplementedError
 
     def smethod():
         """static method-to-be"""
diff --git a/hello.py b/hello.py
index dc8227b07..771e2fe00 100644
--- a/hello.py
+++ b/hello.py
@@ -17,7 +17,7 @@ def __init__(self):
         self.limits = (1, 10)
 
     def get_number(self, min_max):
-        raise NotImplemented
+        raise NotImplementedError
 
     def smethod():
         """static method-to-be"""