diff --git a/pyActigraphy/io/bba/bba.py b/pyActigraphy/io/bba/bba.py
index c1a0b46..a6881ee 100644
--- a/pyActigraphy/io/bba/bba.py
+++ b/pyActigraphy/io/bba/bba.py
@@ -1,11 +1,10 @@
+import importlib
 import json
 import os
 import pandas as pd
 import re
 
 from ..base import BaseRaw
-from accelerometer.utils import date_parser
-from accelerometer.summarisation import imputeMissing
 
 
 class RawBBA(BaseRaw):
@@ -69,6 +68,18 @@ def __init__(
         use_metadata_json=True,
         metadata_fname=None
     ):
+        # The accelerometer package causes some dependency conflicts,
+        # so instead of always including it as a hard dependency, we
+        # try to import it as an optional one. Users with BBA files
+        # likely already have accelerometer installed, or should be
+        # able to sort out the dependency conflicts as needed.
+        try:
+            utils = importlib.import_module('accelerometer.utils')
+        except ModuleNotFoundError as e:
+            raise Exception(
+                'Unable to load the required accelerometer.utils module.'
+                ' Install the package with "pip install accelerometer".'
+            ) from e
 
         # get absolute file path
         input_fname = os.path.abspath(input_fname)
@@ -79,7 +90,7 @@ def __init__(
             engine=engine,
             index_col=['time'],
             parse_dates=['time'],
-            date_parser=date_parser
+            date_parser=utils.date_parser
         )
 
         # read meta-data file (if found):
@@ -139,7 +150,8 @@ def __init__(
 
         # Impute missing data (if required)
         if impute_missing:
-            data = imputeMissing(data)
+            s11n = importlib.import_module('accelerometer.summarization')
+            data = s11n.imputeMissing(data)
 
         # LIGHT
         self.__white_light = self.__extract_baa_data(
@@ -343,6 +355,10 @@ def read_raw_bba(
     r"""Reader function for files produced by the biobankAccelerometerAnalysis
     package.
 
+    Note that the required 'accelerometer' package is not automatically
+    included as a dependency of pyActigraphy. You need to explicitly install
+    it with something like 'pip install accelerometer' to use this function.
+
     Parameters
     ----------
     input_fname: str
diff --git a/setup.py b/setup.py
index 34c0e06..0701c3a 100644
--- a/setup.py
+++ b/setup.py
@@ -108,7 +108,7 @@ def find_version(*file_paths):
     install_requires=[
         'joblib', 'lmfit', 'pandas', 'plotly', 'numba', 'numpy', 'pyexcel',
         'pyexcel-ods3', 'pyexcel-xlsx', 'scipy', 'spm1d', 'statsmodels>=0.10',
-        'stochastic>=0.6.0', 'accelerometer>=6.2.2'
+        'stochastic>=0.6.0'
     ],  # Optional
 
     # Data files included in your packages that need to be installed.