diff --git a/defs/coins/tools/build_coins.py b/defs/coins/tools/build_coins.py
deleted file mode 100755
index cb6a9acb31..0000000000
--- a/defs/coins/tools/build_coins.py
+++ /dev/null
@@ -1,239 +0,0 @@
-#!/usr/bin/env python3
-
-# This script generates coins.json files from the definitions in defs/
-#
-# - `./build_coins.py` generates a big file with everything
-# - `./build_coins.py XXX` generates a file with coins supported by XXX
-#      for example: `./build_coins.py webwallet` or `./build_coins.py trezor1`
-# - `./build_coins.py XXX --defs` also adds protobuf definitions with TOIF icon
-#
-# generated file is coins.json in current directory,
-# and coindefs.json if --def is enabled
-
-import json
-import glob
-import re
-import os
-import sys
-
-if '--defs' in sys.argv:
-    from binascii import unhexlify
-    from hashlib import sha256
-    import ed25519
-    from PIL import Image
-    from trezorlib.protobuf import dump_message
-    from coindef import CoinDef
-    BUILD_DEFS = True
-else:
-    BUILD_DEFS = False
-
-
-def check_type(val, types, nullable=False, empty=False, regex=None, choice=None):  # noqa:E501
-    # check nullable
-    if nullable and val is None:
-        return True
-    # check empty
-    try:
-        if not empty and len(val) == 0:
-            return False
-    except TypeError:
-        pass
-    # check regex
-    if regex is not None:
-        if types is not str:
-            return False
-        m = re.match(regex, val)
-        if not m:
-            return False
-    # check choice
-    if choice is not None:
-        if val not in choice:
-            return False
-    # check type
-    if isinstance(types, list):
-        return True in [isinstance(val, t) for t in types]
-    else:
-        return isinstance(val, types)
-
-
-def validate_coin(coin):
-    assert check_type(coin['coin_name'], str, regex=r'^[A-Z]')
-    assert check_type(coin['coin_shortcut'], str, regex=r'^[A-Zt][A-Z][A-Z]+$')
-    assert check_type(coin['coin_label'], str, regex=r'^[A-Z]')
-    assert check_type(coin['website'], str, regex=r'^http.*[^/]$')
-    assert check_type(coin['github'], str, regex=r'^https://github.com/.*[^/]$')  # noqa:E501
-    assert check_type(coin['maintainer'], str)
-    assert check_type(coin['curve_name'], str, choice=['secp256k1', 'secp256k1_decred', 'secp256k1_groestl'])  # noqa:E501
-    assert check_type(coin['address_type'], int)
-    assert check_type(coin['address_type_p2sh'], int)
-    assert coin['address_type'] != coin['address_type_p2sh']
-    assert check_type(coin['maxfee_kb'], int)
-    assert check_type(coin['minfee_kb'], int)
-    assert coin['maxfee_kb'] >= coin['minfee_kb']
-    assert check_type(coin['hash_genesis_block'], str, regex=r'^[0-9a-f]{64}$')
-    assert check_type(coin['xprv_magic'], int)
-    assert check_type(coin['xpub_magic'], int)
-    assert check_type(coin['xpub_magic_segwit_p2sh'], int, nullable=True)
-    assert check_type(coin['xpub_magic_segwit_native'], int, nullable=True)
-    assert coin['xprv_magic'] != coin['xpub_magic']
-    assert coin['xprv_magic'] != coin['xpub_magic_segwit_p2sh']
-    assert coin['xprv_magic'] != coin['xpub_magic_segwit_native']
-    assert coin['xpub_magic'] != coin['xpub_magic_segwit_p2sh']
-    assert coin['xpub_magic'] != coin['xpub_magic_segwit_native']
-    assert coin['xpub_magic_segwit_p2sh'] is None or coin['xpub_magic_segwit_native'] is None or coin['xpub_magic_segwit_p2sh'] != coin['xpub_magic_segwit_native']  # noqa:E501
-    assert check_type(coin['slip44'], int)
-    assert check_type(coin['segwit'], bool)
-    assert check_type(coin['decred'], bool)
-    assert check_type(coin['fork_id'], int, nullable=True)
-    assert check_type(coin['force_bip143'], bool)
-    assert check_type(coin['version_group_id'], int, nullable=True)
-    assert check_type(coin['default_fee_b'], dict)
-    assert check_type(coin['dust_limit'], int)
-    assert check_type(coin['blocktime_seconds'], int)
-    assert check_type(coin['signed_message_header'], str)
-    assert check_type(coin['address_prefix'], str, regex=r'^.*:$')
-    assert check_type(coin['min_address_length'], int)
-    assert check_type(coin['max_address_length'], int)
-    assert coin['max_address_length'] >= coin['min_address_length']
-    assert check_type(coin['bech32_prefix'], str, nullable=True)
-    assert check_type(coin['cashaddr_prefix'], str, nullable=True)
-    assert check_type(coin['bitcore'], list, empty=True)
-    for bc in coin['bitcore']:
-        assert not bc.endswith('/')
-
-
-def validate_icon(icon):
-    assert icon.size == (96, 96)
-    assert icon.mode == 'RGBA'
-
-
-class Writer:
-
-    def __init__(self):
-        self.buf = bytearray()
-
-    def write(self, buf):
-        self.buf.extend(buf)
-
-
-def serialize(coin, icon):
-    c = dict(coin)
-    c['signed_message_header'] = c['signed_message_header'].encode()
-    c['hash_genesis_block'] = unhexlify(c['hash_genesis_block'])
-    c['icon'] = icon
-    msg = CoinDef(**c)
-    w = Writer()
-    dump_message(w, msg)
-    return bytes(w.buf)
-
-
-def sign(data):
-    h = sha256(data).digest()
-    sign_key = ed25519.SigningKey(b'A' * 32)
-    return sign_key.sign(h)
-
-
-# conversion copied from trezor-core/tools/png2toi
-# TODO: extract into common module in python-trezor
-def convert_icon(icon):
-    import struct
-    import zlib
-    w, h = 32, 32
-    icon = icon.resize((w, h), Image.LANCZOS)
-    # remove alpha channel, replace with black
-    bg = Image.new('RGBA', icon.size, (0, 0, 0, 255))
-    icon = Image.alpha_composite(bg, icon)
-    # process pixels
-    pix = icon.load()
-    data = bytes()
-    for j in range(h):
-        for i in range(w):
-            r, g, b, _ = pix[i, j]
-            c = ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | ((b & 0xF8) >> 3)
-            data += struct.pack('>H', c)
-    z = zlib.compressobj(level=9, wbits=10)
-    zdata = z.compress(data) + z.flush()
-    zdata = zdata[2:-4]  # strip header and checksum
-    return zdata
-
-
-def process_json(fn):
-    print(os.path.basename(fn), end=' ... ')
-    j = json.load(open(fn))
-    if BUILD_DEFS:
-        i = Image.open(fn.replace('.json', '.png'))
-        validate_coin(j)
-        validate_icon(i)
-        ser = serialize(j, convert_icon(i))
-        sig = sign(ser)
-        definition = (sig + ser).hex()
-        print('OK')
-        return j, definition
-    else:
-        print('OK')
-        return j, None
-
-
-scriptdir = os.path.dirname(os.path.realpath(__file__))
-
-
-support_json = json.load(open(scriptdir + '/../../support.json'))
-if len(sys.argv) > 1 and not sys.argv[1].startswith('-'):
-    support_list = support_json[sys.argv[1]].keys()
-else:
-    support_list = None
-
-coins = {}
-defs = {}
-for fn in glob.glob(scriptdir + '/../*.json'):
-    c, d = process_json(fn)
-    n = c['coin_name']
-    c['support'] = {}
-    for s in support_json.keys():
-        c['support'][s] = support_json[s][n] if n in support_json[s] else None
-    if support_list is None or n in support_list:
-        coins[n] = c
-        defs[n] = d
-
-json.dump(coins, open('coins.json', 'w'), indent=4, sort_keys=True)
-if BUILD_DEFS:
-    json.dump(defs, open('coindefs.json', 'w'), indent=4, sort_keys=True)
-
-# check for colliding address versions
-at_p2pkh = {}
-at_p2sh = {}
-slip44 = {}
-
-for n, c in coins.items():
-    s = c['slip44']
-    if s not in slip44:
-        slip44[s] = []
-    if not(n.endswith('Testnet') and s == 1):
-        slip44[s].append(n)
-    if c['cashaddr_prefix']:  # skip cashaddr currencies
-        continue
-    a1, a2 = c['address_type'], c['address_type_p2sh']
-    if a1 not in at_p2pkh:
-        at_p2pkh[a1] = []
-    if a2 not in at_p2sh:
-        at_p2sh[a2] = []
-    at_p2pkh[a1].append(n)
-    at_p2sh[a2].append(n)
-
-print()
-print('Colliding address_types for P2PKH:')
-for k, v in at_p2pkh.items():
-    if len(v) >= 2:
-        print('-', k, ':', ','.join(v))
-
-print()
-print('Colliding address_types for P2SH:')
-for k, v in at_p2sh.items():
-    if len(v) >= 2:
-        print('-', k, ':', ','.join(v))
-
-print()
-print('Colliding SLIP44 constants:')
-for k, v in slip44.items():
-    if len(v) >= 2:
-        print('-', k, ':', ','.join(v))
diff --git a/defs/coins/tools/build_coins.py b/defs/coins/tools/build_coins.py
new file mode 120000
index 0000000000..78034573b4
--- /dev/null
+++ b/defs/coins/tools/build_coins.py
@@ -0,0 +1 @@
+../../../tools/build_coins.py
\ No newline at end of file