diff --git a/python/utils.py b/python/utils.py
index af8508ee..4d08046b 100644
--- a/python/utils.py
+++ b/python/utils.py
@@ -12,7 +12,7 @@ def is_even(x):
         return x % 2 == 0
 
     def is_prime(x):
-        if x == 0 or x == 1:
+        if x in (0, 1):
             return False
 
         for i in range(2, x):