diff --git a/ch.py b/ch.py
new file mode 100644
index 0000000..9801fe2
--- /dev/null
+++ b/ch.py
@@ -0,0 +1,82 @@
+import base64
+
+def calcCRC(message):
+    poly = 0x1021
+    reg = 0
+    message += b'\x00\x00'
+    for byte in message:
+        mask = 0x80
+        while(mask > 0):
+            reg <<= 1
+            if byte & mask:
+                reg += 1
+            mask >>= 1
+            if reg > 0xffff:
+                reg &= 0xffff
+                reg ^= poly
+    return reg.to_bytes(2, "big")
+
+def crc16(data: bytes):
+    table = [
+        0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7, 0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD,
+        0xE1CE, 0xF1EF,
+        0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C,
+        0xF3FF, 0xE3DE,
+        0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485, 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF,
+        0xC5AC, 0xD58D,
+        0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4, 0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE,
+        0xD79D, 0xC7BC,
+        0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823, 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969,
+        0xA90A, 0xB92B,
+        0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58,
+        0xBB3B, 0xAB1A,
+        0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B,
+        0x8D68, 0x9D49,
+        0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70, 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A,
+        0x9F59, 0x8F78,
+        0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F, 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025,
+        0x7046, 0x6067,
+        0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E, 0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214,
+        0x6277, 0x7256,
+        0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, 0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447,
+        0x5424, 0x4405,
+        0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676,
+        0x4615, 0x5634,
+        0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1,
+        0x3882, 0x28A3,
+        0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A, 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0,
+        0x2AB3, 0x3A92,
+        0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83,
+        0x1CE0, 0x0CC1,
+        0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2,
+        0x0ED1, 0x1EF0
+    ]
+    crc = 0
+    for byte in data:
+        crc = (crc << 8) ^ table[(crc >> 8) ^ byte]
+        crc &= 0xFFFF
+    return crc.to_bytes(2, 'big')
+
+
+
+address = "EQCx9xXwEZ2qFCUTxyuvLeXeEV6vZT5DVaBXgflwa4kte1s9"
+address_in_bytes = base64.urlsafe_b64decode(address)[1:-2]
+print(address_in_bytes)
+
+new_flag = 0x51.to_bytes(1)
+
+new_address = new_flag + address_in_bytes
+
+print(new_address)
+
+crc = crc16(new_address)
+
+assert crc16(new_address) == calcCRC(new_address)
+
+print(crc16(new_address) == calcCRC(new_address))
+
+print(crc)
+
+new_address += crc
+
+print(base64.urlsafe_b64encode(new_address))
diff --git a/pytonlib/utils/common.py b/pytonlib/utils/common.py
index 613b146..0b513e8 100644
--- a/pytonlib/utils/common.py
+++ b/pytonlib/utils/common.py
@@ -4,9 +4,9 @@
 import base64
 import asyncio
 import struct
-import crc16
 import codecs
 import logging
+from address import calcCRC
 
 from functools import wraps
 
@@ -80,9 +80,9 @@ def raw_to_userfriendly(address, tag=0x11):
 
     short_ints = [j * 256 + i for i, j in zip(*[iter(key)] * 2)]
     payload = struct.pack(f'Bb{"H"*16}', tag, workchain_id, *short_ints)
-    crc = crc16.crc16xmodem(payload)
+    crc = calcCRC(bytearray(payload))
 
-    e_key = payload + struct.pack('>H', crc)
+    e_key = payload + crc
     return base64.urlsafe_b64encode(e_key).decode("utf-8")
 
 
@@ -120,5 +120,4 @@ async def wrapper(*args, **kwargs):
             return result
         #end def
         return wrapper
-    return decorator
-                
\ No newline at end of file
+    return decorator
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
index 0722ab0..b649e81 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,2 @@
-crc16>=0.1.1
 tvm_valuetypes==0.0.10
 requests>=2.27.1
diff --git a/setup.py b/setup.py
index c1d6944..15a270b 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,6 @@
     version=version,
     packages=find_packages('.', exclude=['tests']),
     install_requires=[
-        'crc16>=0.1.1',
         'tvm_valuetypes==0.0.10',
         'requests>=2.27.1'
     ],