diff --git a/app/controllers/foreman_tasks/tasks_controller.rb b/app/controllers/foreman_tasks/tasks_controller.rb
index 3c295b7bf..b972cb47c 100644
--- a/app/controllers/foreman_tasks/tasks_controller.rb
+++ b/app/controllers/foreman_tasks/tasks_controller.rb
@@ -69,7 +69,7 @@ def resume
 
     def unlock
       if @dynflow_task.paused?
-        unlock_task(@dynflow_task)
+        @dynflow_task.halt
         render json: { statusText: 'OK' }
       else
         render json: {}, status: :bad_request
@@ -77,8 +77,13 @@ def unlock
     end
 
     def force_unlock
-      unlock_task(@dynflow_task)
-      render json: { statusText: 'OK' }
+      if @dynflow_task.pending?
+        @dynflow_task.halt
+        render json: { statusText: 'OK' }
+      else
+        # Cannot halt an already stopped task
+        render json: {}, status: :bad_request
+      end
     end
 
     # we need do this to make the Foreman helpers working properly
@@ -92,12 +97,6 @@ def resource_class
 
     private
 
-    def unlock_task(task)
-      task.state = :stopped
-      task.locks.destroy_all
-      task.save!
-    end
-
     def respond_with_tasks(scope)
       @tasks = filter(scope, paginate: false).with_duration
       csv_response(@tasks, [:id, :action, :state, :result, 'started_at.in_time_zone', 'ended_at.in_time_zone', :duration, :username], ['Id', 'Action', 'State', 'Result', 'Started At', 'Ended At', 'Duration', 'User'])
diff --git a/app/models/foreman_tasks/task/dynflow_task.rb b/app/models/foreman_tasks/task/dynflow_task.rb
index 937e526f2..2f749d57f 100644
--- a/app/models/foreman_tasks/task/dynflow_task.rb
+++ b/app/models/foreman_tasks/task/dynflow_task.rb
@@ -251,6 +251,10 @@ def self.model_name
       superclass.model_name
     end
 
+    def halt
+      ::ForemanTasks.dynflow.world.halt(external_id)
+    end
+
     private
 
     def string_to_time(zone, time)
diff --git a/foreman-tasks.gemspec b/foreman-tasks.gemspec
index b5d7b768a..bc49b98cf 100644
--- a/foreman-tasks.gemspec
+++ b/foreman-tasks.gemspec
@@ -26,7 +26,7 @@ same resource. It also optionally provides Dynflow infrastructure for using it f
   s.test_files = `git ls-files test`.split("\n")
   s.extra_rdoc_files = Dir['README*', 'LICENSE']
 
-  s.add_dependency "dynflow", '>= 1.8.0'
+  s.add_dependency "dynflow", '>= 1.9.0'
   s.add_dependency 'fugit', '~> 1.8'
   s.add_dependency "get_process_mem" # for memory polling
   s.add_dependency "sinatra" # for Dynflow web console