diff --git a/pyheatpump/config.py b/pyheatpump/config.py
index b50f758..c22955d 100644
--- a/pyheatpump/config.py
+++ b/pyheatpump/config.py
@@ -57,10 +57,6 @@ def save_config():
         config.write(conf_file)
 
 
-def get_mac():
-    return get_config_dict()['heatpump', 'mac_address']
-
-
 def mac_address_init():
     from netifaces import gateways, ifaddresses, AF_INET, AF_LINK
 
@@ -112,6 +108,10 @@ async def config_route(request, *args, **kwargs):
         return await set_config(request)
 
 
+def get_mac():
+    return config.get('heatpump','mac_address')
+
+
 async def mac_route(request, *args, **kwargs):
     if request['method'] == 'GET':
         return PlainTextResponse(get_mac())
diff --git a/tests/test_config.py b/tests/test_config.py
index 191162b..d2f183e 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -81,12 +81,24 @@ def test_set_config(tmpconf):
 
 
 def test_mac_address(testdir, tmpconf):
+    c = TestClient(app)
+    _, tmpconf = mkstemp()
+    CONFIG_FILES.append(tmpconf)
+
     mac_address = mac_address_init()
     assert type(get_config_dict()) == dict
-    d_config =get_config_dict()
+    d_config = get_config_dict()
 
     assert d_config['heatpump']['mac_address'] == mac_address
 
+    resp = c.get('/mac')
+    assert resp.status_code  == 200
+    mac_address = resp.content.decode()
+
+    assert d_config['heatpump']['mac_address'] == mac_address
+
+
+
 
 def test_last_update(testdir, tmpconf):
     c = TestClient(app)