diff --git a/py_lets_be_rational/constants.py b/py_lets_be_rational/constants.py
index 7fbd180..9255825 100644
--- a/py_lets_be_rational/constants.py
+++ b/py_lets_be_rational/constants.py
@@ -29,11 +29,12 @@
 
 from __future__ import absolute_import
 
-from _testcapi import DBL_MIN, DBL_MAX
-
 import sys
 from math import sqrt
 
+DBL_MIN = sys.float_info.min
+DBL_MAX = sys.float_info.max
+
 DBL_EPSILON = sys.float_info.epsilon
 
 SQRT_DBL_EPSILON = sqrt(DBL_EPSILON)