diff --git a/src/bloom_filter/bloom_filter.py b/src/bloom_filter/bloom_filter.py
index e16c952..a2146a2 100644
--- a/src/bloom_filter/bloom_filter.py
+++ b/src/bloom_filter/bloom_filter.py
@@ -81,7 +81,7 @@ class Mmap_backend(object):
         Please note that this has only been tested on Linux so far: 2    -11-01.
         """
 
-        effs = 2 ^ 8 - 1
+        effs = 2 ** 8 - 1
 
         def __init__(self, num_bits, filename):
             self.num_bits = num_bits