diff --git a/app/assets/javascripts/app/controllers/_ui_element/core_workflow_condition.coffee b/app/assets/javascripts/app/controllers/_ui_element/core_workflow_condition.coffee
index 6cedd5b90..24d8de723 100644
--- a/app/assets/javascripts/app/controllers/_ui_element/core_workflow_condition.coffee
+++ b/app/assets/javascripts/app/controllers/_ui_element/core_workflow_condition.coffee
@@ -50,15 +50,15 @@ class App.UiElement.core_workflow_condition extends App.UiElement.ApplicationSel
 
     operatorsType =
       'active$': ['is']
-      'boolean$': ['is', 'is not', 'is set', 'not set']
-      'integer$': ['is', 'is not', 'is set', 'not set']
-      '^select$': ['is', 'is not', 'is set', 'not set']
-      '^tree_select$': ['is', 'is not', 'is set', 'not set']
-      '^(input|textarea|richtext)$': ['is', 'is not', 'is set', 'not set', 'regex match', 'regex mismatch']
+      'boolean$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
+      'integer$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
+      '^select$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
+      '^tree_select$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
+      '^(input|textarea|richtext)$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to', 'regex match', 'regex mismatch']
 
     operatorsName =
-      '_id$': ['is', 'is not', 'is set', 'not set']
-      '_ids$': ['is', 'is not', 'is set', 'not set']
+      '_id$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
+      '_ids$': ['is', 'is not', 'is set', 'not set', 'has changed', 'changed to']
 
     # merge config
     elements = {}
@@ -175,7 +175,7 @@ class App.UiElement.core_workflow_condition extends App.UiElement.ApplicationSel
     currentOperator = elementRow.find('.js-operator option:selected').attr('value')
     name            = @buildValueName(elementFull, elementRow, groupAndAttribute, elements, meta, attribute)
 
-    if _.contains(['is set', 'not set'], currentOperator)
+    if _.contains(['is set', 'not set', 'has changed'], currentOperator)
       elementRow.find('.js-value').addClass('hide').html('<input type="hidden" name="' + name + '" value="true" />')
       return
 
diff --git a/app/assets/javascripts/app/controllers/_ui_element/core_workflow_perform.coffee b/app/assets/javascripts/app/controllers/_ui_element/core_workflow_perform.coffee
index 1e1969ff7..7ac20494c 100644
--- a/app/assets/javascripts/app/controllers/_ui_element/core_workflow_perform.coffee
+++ b/app/assets/javascripts/app/controllers/_ui_element/core_workflow_perform.coffee
@@ -128,7 +128,7 @@ class App.UiElement.core_workflow_perform extends App.UiElement.ApplicationSelec
     super(elementFull, elementRow, groupAndAttribute, elements, meta, attribute)
 
   @buildValueConfigMultiple: (config, meta) ->
-    if _.contains(['add_option', 'remove_option', 'set_fixed_to'], meta.operator)
+    if _.contains(['add_option', 'remove_option', 'set_fixed_to', 'select'], meta.operator)
       config.multiple = true
       config.nulloption = true
     else
diff --git a/app/assets/javascripts/app/controllers/ticket_zoom/form_handler_core_workflow.coffee b/app/assets/javascripts/app/controllers/ticket_zoom/form_handler_core_workflow.coffee
index fec12385a..558b72406 100644
--- a/app/assets/javascripts/app/controllers/ticket_zoom/form_handler_core_workflow.coffee
+++ b/app/assets/javascripts/app/controllers/ticket_zoom/form_handler_core_workflow.coffee
@@ -305,6 +305,11 @@ class App.FormHandlerCoreWorkflow
       screen: ui.screen
     }
 
+    # send last changed attribute only once for has changed condition
+    if ui.lastChangedAttribute
+      requestData.last_changed_attribute = ui.lastChangedAttribute
+      ui.lastChangedAttribute            = '-'
+
     if App.FormHandlerCoreWorkflow.useWebSockets()
       App.WebSocket.send(requestData)
     else
diff --git a/app/models/core_workflow/condition.rb b/app/models/core_workflow/condition.rb
index f2dd9676b..01dc07341 100644
--- a/app/models/core_workflow/condition.rb
+++ b/app/models/core_workflow/condition.rb
@@ -8,7 +8,7 @@ class CoreWorkflow::Condition
   def initialize(result_object:, workflow:)
     @user             = result_object.user
     @payload          = result_object.payload
-    @workflow = workflow
+    @workflow         = workflow
     @attribute_object = result_object.attributes
     @result_object    = result_object
     @check            = nil
diff --git a/app/models/core_workflow/condition/backend.rb b/app/models/core_workflow/condition/backend.rb
index fa7e474b2..b3bcd7d9c 100644
--- a/app/models/core_workflow/condition/backend.rb
+++ b/app/models/core_workflow/condition/backend.rb
@@ -10,6 +10,10 @@ class CoreWorkflow::Condition::Backend
 
   attr_reader :value
 
+  def field
+    @key.sub(%r{.*\.}, '')
+  end
+
   def object?(object)
     @condition_object.attributes.instance_of?(object)
   end
diff --git a/app/models/core_workflow/condition/changed_to.rb b/app/models/core_workflow/condition/changed_to.rb
new file mode 100644
index 000000000..4e5827563
--- /dev/null
+++ b/app/models/core_workflow/condition/changed_to.rb
@@ -0,0 +1,9 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+class CoreWorkflow::Condition::ChangedTo < CoreWorkflow::Condition::Backend
+  def match
+    return if !CoreWorkflow::Condition::HasChanged.new(condition_object: @condition_object, key: @key, condition: @condition, value: @value).match
+
+    CoreWorkflow::Condition::Is.new(condition_object: @condition_object, key: @key, condition: @condition, value: @value).match
+  end
+end
diff --git a/app/models/core_workflow/condition/has_changed.rb b/app/models/core_workflow/condition/has_changed.rb
new file mode 100644
index 000000000..150233d1a
--- /dev/null
+++ b/app/models/core_workflow/condition/has_changed.rb
@@ -0,0 +1,9 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+class CoreWorkflow::Condition::HasChanged < CoreWorkflow::Condition::Backend
+  def match
+    return if @condition_object.payload['last_changed_attribute'] != field
+
+    true
+  end
+end
diff --git a/app/models/core_workflow/result/fill_in.rb b/app/models/core_workflow/result/fill_in.rb
index cd9c00da4..8b6a34031 100644
--- a/app/models/core_workflow/result/fill_in.rb
+++ b/app/models/core_workflow/result/fill_in.rb
@@ -11,7 +11,7 @@ class CoreWorkflow::Result::FillIn < CoreWorkflow::Result::Backend
   end
 
   def skip?
-    return true if fill_in_value.blank?
+    return true if fill_in_value.nil?
     return true if params_set?
     return true if fill_in_set?
 
diff --git a/app/models/core_workflow/result/select.rb b/app/models/core_workflow/result/select.rb
index 24ce3e5fc..695151dc9 100644
--- a/app/models/core_workflow/result/select.rb
+++ b/app/models/core_workflow/result/select.rb
@@ -11,7 +11,7 @@ class CoreWorkflow::Result::Select < CoreWorkflow::Result::Backend
   end
 
   def skip?
-    return true if select_value.blank?
+    return true if select_value.nil?
     return true if params_set?
     return true if select_set?
 
diff --git a/spec/models/core_workflow_spec.rb b/spec/models/core_workflow_spec.rb
index 065bb5c7c..31bc345fd 100644
--- a/spec/models/core_workflow_spec.rb
+++ b/spec/models/core_workflow_spec.rb
@@ -1752,4 +1752,64 @@ RSpec.describe CoreWorkflow, type: :model do
       expect(result[:restrict_values]['owner_id']).to eq([''])
     end
   end
+
+  describe 'Add clear selection action or has changed condition #3821' do
+    let!(:workflow_has_changed) do
+      create(:core_workflow,
+             object:             'Ticket',
+             condition_selected: {
+               'ticket.priority_id': {
+                 operator: 'has_changed',
+               },
+             })
+    end
+    let!(:workflow_changed_to) do
+      create(:core_workflow,
+             object:             'Ticket',
+             condition_selected: {
+               'ticket.priority_id': {
+                 operator: 'changed_to',
+                 value:    [ Ticket::Priority.find_by(name: '3 high').id.to_s ]
+               },
+             })
+    end
+
+    context 'when priority changed' do
+      let(:payload) do
+        base_payload.merge('last_changed_attribute' => 'priority_id', 'params' => { 'priority_id' => Ticket::Priority.find_by(name: '3 high').id.to_s })
+      end
+
+      it 'does match on condition has changed' do
+        expect(result[:matched_workflows]).to include(workflow_has_changed.id)
+      end
+
+      it 'does match on condition changed to' do
+        expect(result[:matched_workflows]).to include(workflow_changed_to.id)
+      end
+    end
+
+    context 'when nothing changed' do
+      it 'does not match on condition has changed' do
+        expect(result[:matched_workflows]).not_to include(workflow_has_changed.id)
+      end
+
+      it 'does not match on condition changed to' do
+        expect(result[:matched_workflows]).not_to include(workflow_changed_to.id)
+      end
+    end
+
+    context 'when state changed' do
+      let(:payload) do
+        base_payload.merge('last_changed_attribute' => 'state_id')
+      end
+
+      it 'does not match on condition has changed' do
+        expect(result[:matched_workflows]).not_to include(workflow_has_changed.id)
+      end
+
+      it 'does not match on condition changed to' do
+        expect(result[:matched_workflows]).not_to include(workflow_changed_to.id)
+      end
+    end
+  end
 end