pygost/gost28147.py               | 12 +++---------
 pygost/gost341194.py              |  3 +--
 pygost/stubs/pygost/gost28147.pyi |  3 ---

diff --git a/pygost/gost28147.py b/pygost/gost28147.py
index a283fd6a108b974a2e5e65ba2f17f8481dedb74fd0e19e478ae8b602f1d23161..0778c8f3adc3408120e3cd15b09110b78747ce6df06835abd7afd2cba1f02ab2 100644
--- a/pygost/gost28147.py
+++ b/pygost/gost28147.py
@@ -186,12 +186,6 @@         (n1 >> 0) & 255, (n1 >> 8) & 255, (n1 >> 16) & 255, (n1 >> 24) & 255,
     )))
 
 
-def addmod(x, y, mod=2 ** 32):
-    """ Modulo adding of two integers
-    """
-    return (x + y) % mod
-
-
 def _shift11(x):
     """ 11-bit cyclic shift
     """
@@ -235,7 +229,7 @@         w[3 + i * 4] << 24 for i in range(8)
     ]
     n1, n2 = ns
     for i in seq:
-        n1, n2 = _shift11(_K(s, addmod(n1, x[i]))) ^ n2, n1
+        n1, n2 = _shift11(_K(s, (n1 + x[i]) % (2 ** 32))) ^ n2, n1
     return n1, n2
 
 
@@ -372,8 +366,8 @@         raise ValueError("No data supplied")
     n2, n1 = encrypt(sbox, key, block2ns(iv))
     gamma = []
     for _ in xrange(0, len(data) + pad_size(len(data), BLOCKSIZE), BLOCKSIZE):
-        n1 = addmod(n1, C2, 2 ** 32)
-        n2 = addmod(n2, C1, 2 ** 32 - 1)
+        n1 = (n1 + C2) % (2 ** 32)
+        n2 = (n2 + C1) % (2 ** 32 - 1)
         gamma.append(ns2block(encrypt(sbox, key, (n1, n2))))
     return strxor(b"".join(gamma), data)
 
diff --git a/pygost/gost341194.py b/pygost/gost341194.py
index e45249feaf687af6f5ab80bd704d7ffecadf5c2596ffcd234fa91ee703201f25..2cb7ba799c427c9b9ce2ed9b08ad0a489911ca5b0533a53d87ab1226a654bb79 100644
--- a/pygost/gost341194.py
+++ b/pygost/gost341194.py
@@ -23,7 +23,6 @@ from copy import copy
 from functools import partial
 from struct import pack
 
-from pygost.gost28147 import addmod
 from pygost.gost28147 import block2ns
 from pygost.gost28147 import encrypt
 from pygost.gost28147 import ns2block
@@ -167,7 +166,7 @@         m = self.data
         for i in xrange(0, len(m), BLOCKSIZE):
             part = m[i:i + BLOCKSIZE][::-1]
             _len += len(part) * 8
-            checksum = addmod(checksum, int(hexenc(part), 16), 2 ** 256)
+            checksum = (checksum + int(hexenc(part), 16)) % (2 ** 256)
             if len(part) < BLOCKSIZE:
                 part = b"\x00" * (BLOCKSIZE - len(part)) + part
             h = _step(h, part, self.sbox)
diff --git a/pygost/stubs/pygost/gost28147.pyi b/pygost/stubs/pygost/gost28147.pyi
index d68d539483a051eb70bf0b2af9dfe59f692d86b1492dd633062e181a888010a2..6483f5135dc4c04d7a51e84d1d35a2d03666abf81c4f1bfbe7a59b12c65a30d7 100644
--- a/pygost/stubs/pygost/gost28147.pyi
+++ b/pygost/stubs/pygost/gost28147.pyi
@@ -16,9 +16,6 @@
 def ns2block(ns: Words) -> bytes: ...
 
 
-def addmod(x: int, y: int, mod: int=...) -> int: ...
-
-
 def validate_key(key: bytes) -> None: ...