diff --git a/management/univention-management-console-module-appcenter/umc/python/appcenter/__init__.py b/management/univention-management-console-module-appcenter/umc/python/appcenter/__init__.py
index 113f254..fcc938d 100644
--- a/management/univention-management-console-module-appcenter/umc/python/appcenter/__init__.py
+++ b/management/univention-management-console-module-appcenter/umc/python/appcenter/__init__.py
@@ -46,7 +46,7 @@ import notifier.threads
 from univention.lib.package_manager import PackageManager, LockError
 from univention.management.console.log import MODULE
 from univention.management.console.modules.decorators import simple_response, sanitize, sanitize_list, multi_response
-from univention.management.console.modules.sanitizers import PatternSanitizer, MappingSanitizer, DictSanitizer, StringSanitizer, ChoicesSanitizer, ListSanitizer, EmailSanitizer
+from univention.management.console.modules.sanitizers import PatternSanitizer, MappingSanitizer, DictSanitizer, StringSanitizer, ChoicesSanitizer, ListSanitizer, EmailSanitizer, BooleanSanitizer
 from univention.updater import UniventionUpdater
 from univention.updater.errors import ConfigurationError
 import univention.config_registry
@@ -135,42 +135,39 @@ class Instance(umcm.Base):
 		return application.to_dict(self.package_manager)
 		return props
 
-	@sanitize(
-		function=ChoicesSanitizer(['install', 'update'], required=True),
-		application=StringSanitizer(minimum=1, required=True)
-		)
-	def invoke_dry_run(self, request):
-		MODULE.info('invoke_dry_run')
-		function = request.options.get('function')
-		application_id = request.options.get('application')
-		application = Application.find(application_id)
-
-		if not application:
-			MODULE.info('Application not found')
-			return self.finished(request.id, False)
-		if (function == 'install' and not
-		    application.can_be_installed(self.package_manager)):
-			reason = application.cannot_install_reason(self.package_manager)
-			MODULE.info('Application cannot be installed: %s' % (reason, ))
-			return self.finished(request.id, False)
-		if function == 'update' and not application.can_be_updated():
-			MODULE.info('Application cannot be updated')
-			return self.finished(request.id, False)
-
-		result = application.install_dry_run(self.package_manager, self.component_manager)
-		self.finished(request.id, result)
-
 	@sanitize(function=ChoicesSanitizer(['install', 'uninstall', 'update'], required=True),
-		application=StringSanitizer(minimum=1, required=True)
+	          application=StringSanitizer(minimum=1, required=True),
+	          force=BooleanSanitizer()
 		)
 	def invoke(self, request):
 		function = request.options.get('function')
 		application_id = request.options.get('application')
+		force = request.options.get('force')
 		application = Application.find(application_id)
 		try:
 			# make sure that the application cane be installed/updated
-			can_continue = application is not None and not (function == 'install' and not application.can_be_installed(self.package_manager)) and not (function == 'update' and not application.can_be_updated())
-			self.finished(request.id, can_continue)
+			can_continue = True
+			if not application:
+				MODULE.info('Application not found')
+				can_continue = False
+			if (function == 'install' and not
+			    application.can_be_installed(self.package_manager)):
+				reason = application.cannot_install_reason(self.package_manager)
+				MODULE.info('Application cannot be installed: %s' % (reason, ))
+				can_continue = False
+			if function == 'update' and not application.can_be_updated():
+				MODULE.info('Application cannot be updated')
+				can_continue = False
+			packages = application.install_dry_run(self.package_manager,
+			                                       self.component_manager,
+			                                       remove_component=False)
+			if not force and (packages['remove'] or packages['broken']):
+				can_continue = False
+
+			result = {'success': can_continue,
+			          'packages': packages, }
+			self.finished(request.id, result)
+
 			if can_continue:
 				def _thread(module, application, function):
 					with module.package_manager.locked(reset_status=True, set_finished=True):
diff --git a/management/univention-management-console-module-appcenter/umc/python/appcenter/app_center.py b/management/univention-management-console-module-appcenter/umc/python/appcenter/app_center.py
index 455d7cd..3d7bfa1 100644
--- a/management/univention-management-console-module-appcenter/umc/python/appcenter/app_center.py
+++ b/management/univention-management-console-module-appcenter/umc/python/appcenter/app_center.py
@@ -439,7 +439,7 @@ class Application(object):
 		self._send_information('uninstall', status)
 		return status == 200
 
-	def install_dry_run(self, package_manager, component_manager):
+	def install_dry_run(self, package_manager, component_manager, remove_component=True):
 		MODULE.info('Invoke install_dry_run')
 		result = None
 		try:
@@ -465,10 +465,11 @@ class Application(object):
 			result = dict(zip(['install', 'remove', 'broken', ], result))
 			MODULE.info('Package changes: %s' % (result, ))
 
-			# remove the newly added component
-			MODULE.info('Remove component: %s' % (self.component_id, ))
-			component_manager.remove_app(self)
-			package_manager.update()
+			if remove_component and not result['remove'] and not result['broken']:
+				# remove the newly added component
+				MODULE.info('Remove component: %s' % (self.component_id, ))
+				component_manager.remove_app(self)
+				package_manager.update()
 		except:
 			MODULE.warn(traceback.format_exc())