diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index f738b28..ae65cd7 100644
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -49,7 +49,7 @@ jobs:
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names
-        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        flake8 . --count --select=E9,F63,F7,F82 --ignore=F821 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
         flake8 --exit-zero --ignore=C901,E121,E123,E126,E133,E226,E241,E242,E704,W503,W504,W505 --format=pylint --output-file=output_flake.txt --exclude=*.pyc app/src/
     - name: Test with pytest
diff --git a/app/requirements-test.txt b/app/requirements-test.txt
index 89e69c1..dd4dfbd 100644
--- a/app/requirements-test.txt
+++ b/app/requirements-test.txt
@@ -1,4 +1,4 @@
-    flake8==7.1.2
+    flake8==7.2.0
     pytest==8.3.5
     pytest-asyncio==0.26.0
     pytest-cov==6.1.0
diff --git a/app/tests/test_async_stream.py b/app/tests/test_async_stream.py
index 3f4db93..8d0fa7f 100644
--- a/app/tests/test_async_stream.py
+++ b/app/tests/test_async_stream.py
@@ -84,7 +84,10 @@ async def test_close_cb():
         return 0.1
     def closed():
         nonlocal cnt
-        nonlocal ifc
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.close()  # clears the closed callback
         cnt += 1
     
@@ -113,7 +116,6 @@ async def test_close_cb():
 
 @pytest.mark.asyncio
 async def test_read():
-    global test
     assert asyncio.get_running_loop()
     reader = FakeReader()
     reader.test  = FakeReader.RD_TEST_13_BYTES
@@ -124,11 +126,13 @@ async def test_read():
         return 1
     def closed():
         nonlocal cnt
-        nonlocal ifc
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.close()  # clears the closed callback
         cnt += 1
     def app_read():
-        nonlocal ifc
         ifc.proc_start -= 3
         return 0.01  # async wait of 0.01 
     cnt = 0
@@ -151,7 +155,6 @@ async def test_read():
 
 @pytest.mark.asyncio
 async def test_write():
-    global test
     assert asyncio.get_running_loop()
     reader = FakeReader()
     reader.test  = FakeReader.RD_TEST_13_BYTES
@@ -162,11 +165,13 @@ async def test_write():
         return 1
     def closed():
         nonlocal cnt
-        nonlocal ifc
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.close()  # clears the closed callback
         cnt += 1
     def app_read():
-        nonlocal ifc
         ifc.proc_start -= 3
         return 0.01  # async wait of 0.01 
     
@@ -203,7 +208,6 @@ async def test_publ_mqtt_cb():
         return 0.1
     async def publ_mqtt():
         nonlocal cnt
-        nonlocal ifc
         cnt += 1
     
     cnt = 0
@@ -233,7 +237,10 @@ async def test_create_remote_cb():
         return 0.1
     async def create_remote():
         nonlocal cnt
-        nonlocal ifc
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.close()  # clears the closed callback
         cnt += 1
     
@@ -255,7 +262,6 @@ async def test_create_remote_cb():
 
 @pytest.mark.asyncio
 async def test_sw_exception():
-    global test
     assert asyncio.get_running_loop()
     reader = FakeReader()
     reader.test  = FakeReader.RD_TEST_SW_EXCEPT
@@ -266,7 +272,10 @@ async def test_sw_exception():
         return 1
     def closed():
         nonlocal cnt
-        nonlocal ifc
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.close()  # clears the closed callback
         cnt += 1
     cnt = 0
@@ -285,7 +294,6 @@ async def test_sw_exception():
 
 @pytest.mark.asyncio
 async def test_os_error():
-    global test
     assert asyncio.get_running_loop()
     reader = FakeReader()
     reader.test  = FakeReader.RD_TEST_OS_ERROR
@@ -293,12 +301,11 @@ async def test_os_error():
     reader.on_recv.set()
     writer =  FakeWriter()
     cnt = 0
+
     def timeout():
         return 1
     def closed():
         nonlocal cnt
-        nonlocal ifc
-        ifc.close()  # clears the closed callback
         cnt += 1
     cnt = 0
     ifc =  AsyncStreamClient(reader, writer, None, closed)
@@ -361,10 +368,13 @@ async def test_forward():
     assert asyncio.get_running_loop()
     remote = StreamPtr(None)
     cnt = 0
-
     async def _create_remote():
-        nonlocal cnt, remote, ifc
+        nonlocal cnt
         create_remote(remote, TestType.FWD_NO_EXCPT)
+        # The callback will be called after the AsyncStreamServer
+        # constructer has finished and so ifc must be defined in the
+        # upper scope
+        assert "ifc" in locals()
         ifc.fwd_add(b'test-forward_msg2 ')
         cnt += 1
     
@@ -382,7 +392,7 @@ async def test_forward_with_conn():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote, ifc
+        nonlocal cnt
         cnt += 1
     
     cnt = 0
@@ -417,7 +427,7 @@ async def test_forward_sw_except():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_SW_EXCPT)
         cnt += 1
     
@@ -435,7 +445,7 @@ async def test_forward_os_error():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_OS_ERROR)
         cnt += 1
     
@@ -453,7 +463,7 @@ async def test_forward_os_error2():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_OS_ERROR, True)
         cnt += 1
     
@@ -471,7 +481,7 @@ async def test_forward_os_error3():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_OS_ERROR_NO_STREAM)
         cnt += 1
     
@@ -489,7 +499,7 @@ async def test_forward_runtime_error():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_RUNTIME_ERROR)
         cnt += 1
     
@@ -507,7 +517,7 @@ async def test_forward_runtime_error2():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_RUNTIME_ERROR, True)
         cnt += 1
     
@@ -525,7 +535,7 @@ async def test_forward_runtime_error3():
     cnt = 0
 
     async def _create_remote():
-        nonlocal cnt, remote
+        nonlocal cnt
         create_remote(remote, TestType.FWD_RUNTIME_ERROR_NO_STREAM, True)
         cnt += 1
     
@@ -543,7 +553,7 @@ async def test_forward_resp():
     cnt = 0
 
     def _close_cb():
-        nonlocal cnt, remote, ifc
+        nonlocal cnt
         cnt += 1
     
     cnt = 0
@@ -559,9 +569,8 @@ async def test_forward_resp2():
     assert asyncio.get_running_loop()
     remote = StreamPtr(None)
     cnt = 0
-
     def _close_cb():
-        nonlocal cnt, remote, ifc
+        nonlocal cnt
         cnt += 1
     
     cnt = 0
@@ -571,3 +580,4 @@ async def test_forward_resp2():
     await ifc.client_loop('')
     assert cnt == 1
     del ifc
+ 
\ No newline at end of file
diff --git a/app/tests/test_inverter_base.py b/app/tests/test_inverter_base.py
index 15b14bf..0de04db 100644
--- a/app/tests/test_inverter_base.py
+++ b/app/tests/test_inverter_base.py
@@ -85,7 +85,6 @@ def patch_open_connection():
         return FakeReader(), FakeWriter()
     
     def new_open(host: str, port: int):
-        global test
         if test == MockType.RD_TEST_TIMEOUT:
             raise ConnectionRefusedError
         elif test == MockType.RD_TEST_EXCEPT:
@@ -318,7 +317,7 @@ async def test_remote_conn_to_loopback(config_conn, patch_open_connection):
     assert cnt == 0
 
 @pytest.mark.asyncio
-async def test_remote_conn_to_None(config_conn, patch_open_connection):
+async def test_remote_conn_to_none(config_conn, patch_open_connection):
     '''check if get_extra_info() return None in case of an error'''
     _ = config_conn
     _ = patch_open_connection
diff --git a/app/tests/test_inverter_g3.py b/app/tests/test_inverter_g3.py
index cb83639..e591d04 100644
--- a/app/tests/test_inverter_g3.py
+++ b/app/tests/test_inverter_g3.py
@@ -85,7 +85,6 @@ def patch_open_connection():
         return FakeReader(), FakeWriter()
     
     def new_open(host: str, port: int):
-        global test
         if test == MockType.RD_TEST_TIMEOUT:
             raise ConnectionRefusedError
         elif test == MockType.RD_TEST_EXCEPT:
diff --git a/app/tests/test_inverter_g3p.py b/app/tests/test_inverter_g3p.py
index 9ad5fc2..5b19121 100644
--- a/app/tests/test_inverter_g3p.py
+++ b/app/tests/test_inverter_g3p.py
@@ -84,7 +84,6 @@ def patch_open_connection():
         return FakeReader(), FakeWriter()
     
     def new_open(host: str, port: int):
-        global test
         if test == MockType.RD_TEST_TIMEOUT:
             raise ConnectionRefusedError
         elif test == MockType.RD_TEST_EXCEPT:
diff --git a/app/tests/test_mqtt.py b/app/tests/test_mqtt.py
index 9560767..85f0ab2 100644
--- a/app/tests/test_mqtt.py
+++ b/app/tests/test_mqtt.py
@@ -96,7 +96,6 @@ def test_native_client(test_hostname, test_port):
 
 @pytest.mark.asyncio
 async def test_mqtt_connection(config_mqtt_conn):
-    global NO_MOSQUITTO_TEST
     if NO_MOSQUITTO_TEST:
         pytest.skip('skipping, since Mosquitto is not reliable at the moment')
 
@@ -122,7 +121,6 @@ async def test_mqtt_connection(config_mqtt_conn):
 
 @pytest.mark.asyncio
 async def test_ha_reconnect(config_mqtt_conn):
-    global NO_MOSQUITTO_TEST
     if NO_MOSQUITTO_TEST:
         pytest.skip('skipping, since Mosquitto is not reliable at the moment')