diff --git a/physutils/io.py b/physutils/io.py
index 76a7f75..3cb8f79 100644
--- a/physutils/io.py
+++ b/physutils/io.py
@@ -9,7 +9,6 @@
 import os.path as op
 
 import numpy as np
-from bids import BIDSLayout
 from loguru import logger
 
 from physutils import physio
@@ -28,7 +27,7 @@ def load_from_bids(
     suffix="physio",
 ):
     """
-    Load physiological data from BIDS-formatted directory
+    Load physiological data from BIDS-formatted directory.
 
     Parameters
     ----------
@@ -50,6 +49,12 @@ def load_from_bids(
     data : :class:`physutils.Physio`
         Loaded physiological data
     """
+    try:
+        from bids import BIDSLayout
+    except ImportError:
+        raise ImportError(
+            "To use BIDS-based feature, pybids must be installed. Install manually or with `pip install physutils[bids]`"
+        )
 
     # check if file exists and is in BIDS format
     if not op.exists(bids_path):
diff --git a/physutils/tasks.py b/physutils/tasks.py
index 3da6c56..686db19 100644
--- a/physutils/tasks.py
+++ b/physutils/tasks.py
@@ -11,7 +11,6 @@
 
 # from loguru import logger
 
-
 try:
     from pydra import task
 except ImportError:
diff --git a/setup.cfg b/setup.cfg
index 86e5486..619fbf5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -24,8 +24,6 @@ install_requires =
     matplotlib
     numpy >=1.9.3
     loguru
-    pydra
-    pybids
 tests_require =
     pytest >=3.6
 test_suite = pytest
@@ -34,6 +32,10 @@ packages = find:
 include_package_data = True
 
 [options.extras_require]
+pydra =
+    pydra
+bids =
+    pybids
 doc =
     sphinx >=2.0
     sphinx-argparse
@@ -49,6 +51,8 @@ test =
     scipy
     pytest >=5.3
     pytest-cov
+    %(pydra)s
+    %(bids)s
     %(style)s
 devtools =
     pre-commit