diff --git a/api/v1alpha1/horizontalrunnerautoscaler_types.go b/api/v1alpha1/horizontalrunnerautoscaler_types.go
index 74a37e90..89a23584 100644
--- a/api/v1alpha1/horizontalrunnerautoscaler_types.go
+++ b/api/v1alpha1/horizontalrunnerautoscaler_types.go
@@ -69,10 +69,9 @@ type ScaleUpTrigger struct {
 }
 
 type GitHubEventScaleUpTriggerSpec struct {
-	CheckRun         *CheckRunSpec         `json:"checkRun,omitempty"`
-	PullRequest      *PullRequestSpec      `json:"pullRequest,omitempty"`
-	Push             *PushSpec             `json:"push,omitempty"`
-	WorkflowDispatch *WorkflowDispatchSpec `json:"push,omitempty"`
+	CheckRun    *CheckRunSpec    `json:"checkRun,omitempty"`
+	PullRequest *PullRequestSpec `json:"pullRequest,omitempty"`
+	Push        *PushSpec        `json:"push,omitempty"`
 }
 
 // https://docs.github.com/en/actions/reference/events-that-trigger-workflows#check_run
@@ -102,13 +101,6 @@ type PullRequestSpec struct {
 type PushSpec struct {
 }
 
-// WorkflowDispatchSpec is the condition for triggering scale-up on push event
-// Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#workflow_dispatch
-type WorkflowDispatchSpec struct {
-	Branches       []string `json:"branches,omitempty"`
-	BranchesIgnore []string `json:"branchesIgnore,omitempty"`
-}
-
 // CapacityReservation specifies the number of replicas temporarily added
 // to the scale target until ExpirationTime.
 type CapacityReservation struct {
diff --git a/config/crd/bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml b/config/crd/bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml
index f8167513..3b82566a 100644
--- a/config/crd/bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml
+++ b/config/crd/bases/actions.summerwind.dev_horizontalrunnerautoscalers.yaml
@@ -157,18 +157,6 @@ spec:
                           push:
                             description: PushSpec is the condition for triggering scale-up on push event Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#push
                             type: object
-                          workflowDispatch:
-                            description: WorkflowDispatchSpec is the condition for triggering scale-up on workflow_dispatch event Also see https://docs.github.com/en/actions/reference/events-that-trigger-workflows#workflow_dispatch
-                            properties:
-                              branches:
-                                items:
-                                  type: string
-                                type: array
-                              branchesIgnore:
-                                items:
-                                  type: string
-                                type: array
-                            type: object
                         type: object
                     type: object
                   type: array
diff --git a/controllers/horizontal_runner_autoscaler_webhook.go b/controllers/horizontal_runner_autoscaler_webhook.go
index d8e1ea84..b522906e 100644
--- a/controllers/horizontal_runner_autoscaler_webhook.go
+++ b/controllers/horizontal_runner_autoscaler_webhook.go
@@ -183,15 +183,6 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) Handle(w http.Respons
 				"action", e.GetAction(),
 			)
 		}
-	case *gogithub.WorkflowDispatchEvent:
-		target, err = autoscaler.getScaleUpTarget(
-			context.TODO(),
-			log,
-			e.Repo.GetName(),
-			e.Repo.Owner.GetLogin(),
-			e.Repo.Owner.GetType(),
-			autoscaler.WorkflowDispatchEvent(e),
-		)
 	case *gogithub.WorkflowJobEvent:
 		if workflowJob := e.GetWorkflowJob(); workflowJob != nil {
 			log = log.WithValues(
diff --git a/controllers/horizontal_runner_autoscaler_webhook_on_workflow_dispatch.go b/controllers/horizontal_runner_autoscaler_webhook_on_workflow_dispatch.go
deleted file mode 100644
index 33b123fd..00000000
--- a/controllers/horizontal_runner_autoscaler_webhook_on_workflow_dispatch.go
+++ /dev/null
@@ -1,35 +0,0 @@
-package controllers
-
-import (
-	"github.com/actions-runner-controller/actions-runner-controller/api/v1alpha1"
-	"github.com/google/go-github/v37/github"
-)
-
-// MatchPushEvent()
-func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) MatchWorkflowDispatchEvent(event *github.PushEvent) func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
-	return func(scaleUpTrigger v1alpha1.ScaleUpTrigger) bool {
-		g := scaleUpTrigger.GitHubEvent
-
-		if g == nil {
-			return false
-		}
-
-		WorkflowDispatch := g.WorkflowDispatch
-
-		if WorkflowDispatch == nil {
-			return false
-		}
-
-		// event.Ref = Branch that received dispatch
-		// event.Ref = refs/heads/branch-name
-		if !matchTriggerConditionAgainstEvent(WorkflowDispatch.Branches, event.Ref) {
-			return false
-		}
-
-		if matchTriggerConditionAgainstEvent(WorkflowDispatch.BranchesIgnore, event.Ref) {
-			return false
-		}
-
-		return true
-	}
-}