diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 51ad046..d460683 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -21,7 +21,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
-          pip install -U pytest pytest-cov pyzmq netifaces
+          pip install -U pytest pytest-cov pyzmq netifaces donfig
       - name: Install posttroll
         run: |
           pip install --no-deps -e .
diff --git a/posttroll/__init__.py b/posttroll/__init__.py
index db127d0..b77c34b 100644
--- a/posttroll/__init__.py
+++ b/posttroll/__init__.py
@@ -24,15 +24,17 @@
 
 """Posttroll packages."""
 
+import logging
+import os
 import sys
-
 from datetime import datetime
-import os
-import logging
-from .version import get_versions
 
 import zmq
+from donfig import Config
+
+from .version import get_versions
 
+config = Config('posttroll')
 context = {}
 logger = logging.getLogger(__name__)
 
@@ -74,10 +76,10 @@ def strp_isoformat(strg):
 
 
 def _set_tcp_keepalive(socket):
-    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE, os.environ.get("POSTTROLL_TCP_KEEPALIVE"))
-    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_CNT, os.environ.get("POSTTROLL_TCP_KEEPALIVE_CNT"))
-    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_IDLE, os.environ.get("POSTTROLL_TCP_KEEPALIVE_IDLE"))
-    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_INTVL, os.environ.get("POSTTROLL_TCP_KEEPALIVE_INTVL"))
+    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE, config.get("tcp_keepalive", None))
+    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_CNT, config.get("tcp_keepalive_cnt", None))
+    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_IDLE, config.get("tcp_keepalive_idle", None))
+    _set_int_sockopt(socket, zmq.TCP_KEEPALIVE_INTVL, config.get("tcp_keepalive_intvl", None))
 
 
 def _set_int_sockopt(socket, param, value):
diff --git a/posttroll/publisher.py b/posttroll/publisher.py
index 0ec6216..05ffd21 100644
--- a/posttroll/publisher.py
+++ b/posttroll/publisher.py
@@ -35,6 +35,7 @@
 from posttroll import _set_tcp_keepalive
 from posttroll.message import Message
 from posttroll.message_broadcaster import sendaddressservice
+from posttroll import config
 
 LOGGER = logging.getLogger(__name__)
 
@@ -99,10 +100,8 @@ def __init__(self, address, name="", min_port=None, max_port=None):
 
         # Limit port range or use the defaults when no port is defined
         # by the user
-        min_port = min_port or int(os.environ.get('POSTTROLL_PUB_MIN_PORT',
-                                                  49152))
-        max_port = max_port or int(os.environ.get('POSTTROLL_PUB_MAX_PORT',
-                                                  65536))
+        min_port = min_port or int(config.get('pub_min_port', 49152))
+        max_port = max_port or int(config.get('pub_max_port', 65536))
 
         # Check for port 0 (random port)
         u__ = urlsplit(self.destination)
diff --git a/posttroll/tests/test_pubsub.py b/posttroll/tests/test_pubsub.py
index 6b905b9..483e2ad 100644
--- a/posttroll/tests/test_pubsub.py
+++ b/posttroll/tests/test_pubsub.py
@@ -28,8 +28,11 @@
 from datetime import timedelta
 from threading import Thread, Lock
 import time
+from contextlib import contextmanager
 
+import posttroll
 import pytest
+from donfig import Config
 
 test_lock = Lock()
 
@@ -312,13 +315,14 @@ def test_pub_minmax_port(self):
             # Set the port range to environment variables
             os.environ['POSTTROLL_PUB_MIN_PORT'] = str(port)
             os.environ['POSTTROLL_PUB_MAX_PORT'] = str(port + 1)
-            res = _get_port(min_port=None, max_port=None)
-            if res is False:
-                # The port wasn't free, try again
-                continue
-            # Port was selected, make sure it's within the "range" of one
-            self.assertEqual(res, port)
-            break
+            with posttroll.config.set(pub_min_port=str(port), pub_max_port=str(port + 1)):
+                res = _get_port(min_port=None, max_port=None)
+                if res is False:
+                    # The port wasn't free, try another one
+                    continue
+                # Port was selected, make sure it's within the "range" of one
+                self.assertEqual(res, port)
+                break
 
         # Using range of ports defined at instantation time, this
         # should override environment variables
@@ -636,6 +640,17 @@ def tcp_keepalive_settings(monkeypatch):
     monkeypatch.setenv("POSTTROLL_TCP_KEEPALIVE_CNT", "10")
     monkeypatch.setenv("POSTTROLL_TCP_KEEPALIVE_IDLE", "1")
     monkeypatch.setenv("POSTTROLL_TCP_KEEPALIVE_INTVL", "1")
+    with reset_config_for_tests():
+        yield
+
+
+@contextmanager
+def reset_config_for_tests():
+    """Reset the config for testing."""
+    old_config = posttroll.config
+    posttroll.config = Config("posttroll")
+    yield
+    posttroll.config = old_config
 
 
 @pytest.fixture
@@ -645,6 +660,8 @@ def tcp_keepalive_no_settings(monkeypatch):
     monkeypatch.delenv("POSTTROLL_TCP_KEEPALIVE_CNT", raising=False)
     monkeypatch.delenv("POSTTROLL_TCP_KEEPALIVE_IDLE", raising=False)
     monkeypatch.delenv("POSTTROLL_TCP_KEEPALIVE_INTVL", raising=False)
+    with reset_config_for_tests():
+        yield
 
 
 def test_publisher_tcp_keepalive(tcp_keepalive_settings):
diff --git a/setup.py b/setup.py
index b13e9e1..e80d8d6 100644
--- a/setup.py
+++ b/setup.py
@@ -26,7 +26,7 @@
 import versioneer
 
 
-requirements = ['pyzmq', 'netifaces']
+requirements = ['pyzmq', 'netifaces', "donfig"]
 
 
 setup(name="posttroll",