diff --git a/piker/brokers/config.py b/piker/brokers/config.py
index 22cbfe9c..f1c8a90d 100644
--- a/piker/brokers/config.py
+++ b/piker/brokers/config.py
@@ -1,7 +1,7 @@
 """
 Broker configuration mgmt.
 """
-from os import path, makedirs
+import os
 import configparser
 import click
 from ..log import get_logger
@@ -9,28 +9,46 @@ from ..log import get_logger
 log = get_logger('broker-config')
 
 _config_dir = click.get_app_dir('piker')
-_broker_conf_path = path.join(_config_dir, 'brokers.ini')
+_file_name = 'brokers.ini'
 
 
-def load(path: str = None) -> (configparser.ConfigParser, str):
+def _override_config_dir(
+    path: str
+) -> None:
+    global _config_dir
+    _config_dir = path
+
+
+def get_broker_conf_path():
+    return os.path.join(_config_dir, _file_name)
+
+
+def load(
+    path: str = None
+) -> (configparser.ConfigParser, str):
     """Load broker config.
     """
-    path = path or _broker_conf_path
+    path = path or get_broker_conf_path()
     config = configparser.ConfigParser()
-    read = config.read(path)
+    config.read(path)
     log.debug(f"Read config file {path}")
     return config, path
 
 
-def write(config: configparser.ConfigParser) -> None:
+def write(
+    config: configparser.ConfigParser,
+    path: str = None,
+) -> None:
     """Write broker config to disk.
 
     Create a ``brokers.ini`` file if one does not exist.
     """
-    if not path.isdir(_config_dir):
+    path = path or get_broker_conf_path()
+    dirname = os.path.dirname(path)
+    if not os.path.isdir(dirname):
         log.debug(f"Creating config dir {_config_dir}")
-        makedirs(_config_dir)
+        os.makedirs(dirname)
 
-    log.debug(f"Writing config file {_broker_conf_path}")
-    with open(_broker_conf_path, 'w') as cf:
+    log.debug(f"Writing config file {path}")
+    with open(path, 'w') as cf:
         return config.write(cf)