diff --git a/management/python-notifier/python-notifier b/management/python-notifier/python-notifier
index 5795ab5..054b7e6 160000
--- a/management/python-notifier/python-notifier
+++ b/management/python-notifier/python-notifier
@@ -1 +1 @@
-Subproject commit 5795ab564093bd83bcee204cbf8c6c36044d8cea
+Subproject commit 054b7e686501e219b0ff44244be931c1c0ae6b8e
diff --git a/management/univention-appcenter/python/appcenter/utils.py b/management/univention-appcenter/python/appcenter/utils.py
index 2ff577c..394bec9 100644
--- a/management/univention-appcenter/python/appcenter/utils.py
+++ b/management/univention-appcenter/python/appcenter/utils.py
@@ -94,6 +94,16 @@ def docker_bridge_network_conflict():
 	return False
 
 
+def docker_compose_network_conflict():
+	docker_compose_net = ipaddr.IPv4Network(ucr_get('appcenter/docker/compose/network', '172.16.1.1/16'))
+	for name, iface in interfaces.Interfaces().ipv4_interfaces:
+		if 'network' in iface and 'netmask' in iface:
+			my_net = ipaddr.IPv4Network('%s/%s' % (iface['network'], iface['netmask']))
+			if my_net.overlaps(docker_compose_net):
+				return True
+	return False
+
+
 def app_is_running(app):
 	from univention.appcenter.app_cache import Apps
 	if isinstance(app, basestring):
diff --git a/management/univention-appcenter/umc/python/appcenter/__init__.py b/management/univention-appcenter/umc/python/appcenter/__init__.py
index 2bf70eb..6b287c8 100644
--- a/management/univention-appcenter/umc/python/appcenter/__init__.py
+++ b/management/univention-appcenter/umc/python/appcenter/__init__.py
@@ -63,7 +63,7 @@ from univention.appcenter.exceptions import Abort, NetworkError, AppCenterError
 from univention.appcenter.packages import reload_package_manager, get_package_manager, package_lock, LOCK_FILE
 from univention.appcenter.app_cache import Apps, AppCenterCache, default_server
 from univention.appcenter.udm import _update_modules
-from univention.appcenter.utils import docker_is_running, call_process, docker_bridge_network_conflict, send_information, app_is_running, find_hosts_for_master_packages, get_local_fqdn
+from univention.appcenter.utils import docker_is_running, call_process, docker_bridge_network_conflict, docker_compose_network_conflict, send_information, app_is_running, find_hosts_for_master_packages, get_local_fqdn
 from univention.appcenter.log import get_base_logger, log_to_logfile
 from univention.appcenter.ucr import ucr_instance, ucr_save
 from univention.appcenter.settings import FileSetting, PasswordFileSetting
@@ -274,6 +274,11 @@ class Instance(umcm.Base, ProgressMixin):
 			msg += _('Please either configure a different network for the docker bridge by setting the UCR variable docker/daemon/default/opts/bip to a different network and restart the system,') + ' '
 			msg += _('or disable the docker support in the AppCenter by setting appcenter/docker to false.')
 			raise umcm.UMC_Error(msg)
+		if docker_compose_network_conflict():
+			msg = _('A conflict between the system network settings and the docker compose default network has been detected.') + '\n\n'
+			msg += _('Please either configure a different network for docker compose by setting the UCR variable appcenter/docker/compose/network to a different network and restart the system,') + ' '
+			msg += _('or disable the docker support in the AppCenter by setting appcenter/docker to false.')
+			raise umcm.UMC_Error(msg)
 		if not docker_is_running():
 			MODULE.warn('Docker is not running! Trying to start it now...')
 			call_process(['invoke-rc.d', 'docker', 'start'])
diff --git a/test/ucs-ec2-tools b/test/ucs-ec2-tools
index 94ea10e..fc9f512 160000
--- a/test/ucs-ec2-tools
+++ b/test/ucs-ec2-tools
@@ -1 +1 @@
-Subproject commit 94ea10eef74da3c33258201809030f9fcd7d7a6d
+Subproject commit fc9f512f23cef2d0b39aef0666f3588c21489a9d