diff --git a/minitests/roi_harness/runme.sh b/minitests/roi_harness/runme.sh
index fc64fdca8..8eb39ff59 100755
--- a/minitests/roi_harness/runme.sh
+++ b/minitests/roi_harness/runme.sh
@@ -67,7 +67,7 @@ ${XRAY_VIVADO} -mode batch -source ../runme.tcl
 test -z "$(fgrep CRITICAL vivado.log)"
 
 ${XRAY_BITREAD} -F $XRAY_ROI_FRAMES -o design.bits -z -y design.bit
-python3 ${XRAY_DIR}/utils/bit2fasm.py --verbose design.bit > design.fasm
+python3 -m xc_fasm.bit2fasm --verbose design.bit > design.fasm
 python3 ${XRAY_DIR}/utils/fasm2frames.py design.fasm design.frm
 PYTHONPATH=$PYTHONPATH:$XRAY_DIR/utils python3 ../create_design_json.py \
     --design_info_txt design_info.txt \
diff --git a/minitests/srl/README.md b/minitests/srl/README.md
index c634fe1a3..ec267d080 100644
--- a/minitests/srl/README.md
+++ b/minitests/srl/README.md
@@ -2,4 +2,5 @@
 
 This is a minitest for various SRL configurations.
 
-Uses Yosys to generate EDIF which is then P&R'd by Vivado. The makefile also invokes bit2fasm and segprint
\ No newline at end of file
+Uses Yosys to generate EDIF which is then P&R'd by Vivado.
+The makefile also invokes `xc_fasm.bit2fasm` and `segprint`.
diff --git a/utils/bit2fasm.py b/utils/bit2fasm.py
deleted file mode 100755
index 859ec1096..000000000
--- a/utils/bit2fasm.py
+++ /dev/null
@@ -1,127 +0,0 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
-#
-# Copyright (C) 2017-2020  The Project X-Ray Authors.
-#
-# Use of this source code is governed by a ISC-style
-# license that can be found in the LICENSE file or at
-# https://opensource.org/licenses/ISC
-#
-# SPDX-License-Identifier: ISC
-'''
-Take bitstream .bit files and decode them to FASM.
-'''
-
-import contextlib
-import os
-import fasm
-import fasm.output
-from prjxray import fasm_disassembler
-from prjxray import bitstream
-from prjxray.db import Database
-from prjxray.util import OpenSafeFile
-import subprocess
-import tempfile
-
-
-def bit_to_bits(bitread, part_yaml, bit_file, bits_file, frame_range=None):
-    """ Calls bitread to create bits (ASCII) from bit file (binary) """
-    if frame_range:
-        frame_range_arg = '-F {}'.format(frame_range)
-    else:
-        frame_range_arg = ''
-
-    subprocess.check_output(
-        '{} --part_file {} {} -o {} -z -y {}'.format(
-            bitread, part_yaml, frame_range_arg, bits_file, bit_file),
-        shell=True)
-
-
-def bits_to_fasm(db_root, part, bits_file, verbose, canonical):
-    db = Database(db_root, part)
-    grid = db.grid()
-    disassembler = fasm_disassembler.FasmDisassembler(db)
-
-    with OpenSafeFile(bits_file) as f:
-        bitdata = bitstream.load_bitdata(f)
-
-    model = fasm.output.merge_and_sort(
-        disassembler.find_features_in_bitstream(bitdata, verbose=verbose),
-        zero_function=disassembler.is_zero_feature,
-        sort_key=grid.tile_key,
-    )
-
-    print(fasm.fasm_tuple_to_string(model, canonical=canonical), end='')
-
-
-def main():
-    import argparse
-
-    parser = argparse.ArgumentParser(
-        description='Convert 7-series bit file to FASM.')
-
-    database_dir = os.getenv("XRAY_DATABASE_DIR")
-    database = os.getenv("XRAY_DATABASE")
-    db_root_kwargs = {}
-    if database_dir is None or database is None:
-        db_root_kwargs['required'] = True
-    else:
-        db_root_kwargs['required'] = False
-        db_root_kwargs['default'] = os.path.join(database_dir, database)
-
-    default_part = os.getenv("XRAY_PART")
-    part_kwargs = {}
-    if default_part is None:
-        part_kwargs['required'] = True
-    else:
-        part_kwargs['required'] = False
-        part_kwargs['default'] = default_part
-
-    if os.getenv("XRAY_TOOLS_DIR") is None:
-        default_bitread = 'bitread'
-    else:
-        default_bitread = os.path.join(os.getenv("XRAY_TOOLS_DIR"), 'bitread')
-
-    parser.add_argument('--db-root', help="Database root.", **db_root_kwargs)
-    parser.add_argument(
-        '--bits-file',
-        help="Output filename for bitread output, default is deleted tempfile.",
-        default=None)
-    parser.add_argument(
-        '--part', help="Name of part being targetted.", **part_kwargs)
-    parser.add_argument(
-        '--bitread',
-        help="bitread tool to to use",
-        default=default_bitread)
-    parser.add_argument(
-        '--frame_range', help="Frame range to use with bitread.")
-    parser.add_argument('bit_file', help='')
-    parser.add_argument(
-        '--verbose',
-        help='Print lines for unknown tiles and bits',
-        action='store_true')
-    parser.add_argument(
-        '--canonical', help='Output canonical bitstream.', action='store_true')
-    args = parser.parse_args()
-
-    with contextlib.ExitStack() as stack:
-        if args.bits_file:
-            bits_file = stack.enter_context(open(args.bits_file, 'wb'))
-        else:
-            bits_file = stack.enter_context(tempfile.NamedTemporaryFile())
-
-        bit_to_bits(
-            bitread=args.bitread,
-            part_yaml=os.path.join(args.db_root, args.part, "part.yaml"),
-            bit_file=args.bit_file,
-            bits_file=bits_file.name,
-            frame_range=args.frame_range,
-        )
-
-        bits_to_fasm(
-            args.db_root, args.part, bits_file.name, args.verbose,
-            args.canonical)
-
-
-if __name__ == '__main__':
-    main()
diff --git a/utils/environment.sh b/utils/environment.sh
index 6e246cf89..b318e17df 100644
--- a/utils/environment.sh
+++ b/utils/environment.sh
@@ -6,6 +6,7 @@
 # https://opensource.org/licenses/ISC
 #
 # SPDX-License-Identifier: ISC
+
 XRAY_ENV_PATH="${BASH_SOURCE[0]}"
 while [ -h "$XRAY_ENV_PATH" ]; do # resolve $XRAY_ENV_PATH until the file is no longer a symlink
   XRAY_UTILS_DIR="$( cd -P "$( dirname "$XRAY_ENV_PATH" )" && pwd )"
@@ -23,14 +24,14 @@ if [ -e "${XRAY_DIR}/env/bin/activate" ]; then
   source "${XRAY_DIR}/env/bin/activate"
 fi
 
-# misc
+pip3 install https://github.com/chipsalliance/f4pga-xc-fasm/archive/master.zip
+
 export XRAY_PART_YAML="${XRAY_DATABASE_DIR}/${XRAY_DATABASE}/${XRAY_PART}/part.yaml"
 source $XRAY_UTILS_DIR/environment.python.sh
 
 # Set environment to default output and overwrite localisation settings
 export LC_ALL=C
 
-# tools
 export XRAY_GENHEADER="${XRAY_UTILS_DIR}/genheader.sh"
 export XRAY_BITREAD="${XRAY_TOOLS_DIR}/bitread --part_file ${XRAY_PART_YAML}"
 export XRAY_MERGEDB="bash ${XRAY_UTILS_DIR}/mergedb.sh"
@@ -38,7 +39,7 @@ export XRAY_DBFIXUP="python3 ${XRAY_UTILS_DIR}/dbfixup.py"
 export XRAY_MASKMERGE="bash ${XRAY_UTILS_DIR}/maskmerge.sh"
 export XRAY_SEGMATCH="${XRAY_TOOLS_DIR}/segmatch"
 export XRAY_SEGPRINT="python3 ${XRAY_UTILS_DIR}/segprint.py"
-export XRAY_BIT2FASM="python3 ${XRAY_UTILS_DIR}/bit2fasm.py"
+export XRAY_BIT2FASM="python3 -m xc_fasm.bit2fasm"
 export XRAY_FASM2FRAMES="python3 ${XRAY_UTILS_DIR}/fasm2frames.py"
 export XRAY_BITTOOL="${XRAY_TOOLS_DIR}/bittool"
 export XRAY_BLOCKWIDTH="python3 ${XRAY_UTILS_DIR}/blockwidth.py"