diff --git a/micall/utils/cigar_tools.py b/micall/utils/cigar_tools.py
index 36b829262..92a45e4d8 100644
--- a/micall/utils/cigar_tools.py
+++ b/micall/utils/cigar_tools.py
@@ -8,6 +8,7 @@
 from dataclasses import dataclass
 from functools import cached_property
 from itertools import chain, dropwhile
+from fractions import Fraction
 
 from micall.utils.consensus_aligner import CigarActions
 
@@ -429,7 +430,7 @@ def __add__(self, other):
 
     @property
     def epsilon(self):
-        return 1 / (self.query_length + self.ref_length + 100)
+        return Fraction(1, self.query_length + self.ref_length + 100)
 
 
     def _slice(self, r_st, r_ei, q_st, q_ei) -> 'CigarHit':
@@ -479,7 +480,8 @@ def cut_reference(self, cut_point: float) -> 'CigarHit':
         and that no element is lost.
         """
 
-        if float(cut_point).is_integer():
+        cut_point = Fraction(cut_point)
+        if cut_point.denominator == 1:
             raise ValueError("Cut accepts fractions, not integers")
 
         if self.ref_length == 0 or \