diff --git a/nupic/algorithms/anomaly.py b/nupic/algorithms/anomaly.py
index <HASH>..<HASH> 100644
--- a/nupic/algorithms/anomaly.py
+++ b/nupic/algorithms/anomaly.py
@@ -101,7 +101,7 @@ class Anomaly(object):
       self._buf = numpy.array([0] * self._windowSize, dtype=numpy.float)
       self._i = 0 # index pointer to actual position
     elif slidingWindowSize <= 0:
-      raise ValueException(
+      raise ValueError(
           "Anomaly: if you define slidingWindowSize, it has to be an "
           "integer > 0;  slidingWindowSize=%r" % slidingWindowSize)
     elif slidingWindowSize is not None:
fix: typo in ValueError