diff --git a/pkg/reconciler/pipelinerun/resources/pipelinerunresolution.go b/pkg/reconciler/pipelinerun/resources/pipelinerunresolution.go
index 3de5edd6b41..38b0e45ae55 100644
--- a/pkg/reconciler/pipelinerun/resources/pipelinerunresolution.go
+++ b/pkg/reconciler/pipelinerun/resources/pipelinerunresolution.go
@@ -627,7 +627,8 @@ func resolveTask(
 	pipelineTask v1.PipelineTask,
 ) (*resources.ResolvedTask, error) {
 	rt := &resources.ResolvedTask{}
-	if pipelineTask.TaskRef != nil {
+	switch {
+	case pipelineTask.TaskRef != nil:
 		// If the TaskRun has already a stored TaskSpec in its status, use it as source of truth
 		if taskRun != nil && taskRun.Status.TaskSpec != nil {
 			rt.TaskSpec = taskRun.Status.TaskSpec
@@ -652,8 +653,13 @@ func resolveTask(
 			}
 		}
 		rt.Kind = pipelineTask.TaskRef.Kind
-	} else {
+	case pipelineTask.TaskSpec != nil:
 		rt.TaskSpec = &pipelineTask.TaskSpec.TaskSpec
+	default:
+		// If the alpha feature is enabled, and the user has configured pipelineSpec or pipelineRef, it will enter here.
+		// Currently, the controller is not yet adapted, and to avoid a panic, an error message is provided here.
+		// TODO: Adjust the logic here once the feature is supported in the future.
+		return nil, fmt.Errorf("Currently, Task %q does not support PipelineRef or PipelineSpec, please use TaskRef or TaskSpec instead", pipelineTask.Name)
 	}
 	rt.TaskSpec.SetDefaults(ctx)
 	return rt, nil
diff --git a/pkg/reconciler/pipelinerun/resources/pipelinerunresolution_test.go b/pkg/reconciler/pipelinerun/resources/pipelinerunresolution_test.go
index cc6b38e5c5e..f247fd01c7c 100644
--- a/pkg/reconciler/pipelinerun/resources/pipelinerunresolution_test.go
+++ b/pkg/reconciler/pipelinerun/resources/pipelinerunresolution_test.go
@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"sort"
+	"strings"
 	"testing"
 	"time"
 
@@ -2434,6 +2435,31 @@ func TestResolvePipelineRun_PipelineTaskHasNoResources(t *testing.T) {
 	}
 }
 
+func TestResolvePipelineRun_PipelineTaskHasPipelineRef(t *testing.T) {
+	pt := v1.PipelineTask{
+		Name:        "pipeline-in-pipeline",
+		PipelineRef: &v1.PipelineRef{Name: "pipeline"},
+	}
+
+	getTask := func(ctx context.Context, name string) (*v1.Task, *v1.RefSource, *trustedresources.VerificationResult, error) {
+		return task, nil, nil, nil
+	}
+	getTaskRun := func(name string) (*v1.TaskRun, error) { return &trs[0], nil }
+	pr := v1.PipelineRun{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "pipelinerun",
+		},
+	}
+
+	_, err := ResolvePipelineTask(context.Background(), pr, getTask, getTaskRun, nopGetCustomRun, pt, nil)
+	if err == nil {
+		t.Errorf("Error getting tasks for fake pipeline %s, expected an error but got nil.", p.ObjectMeta.Name)
+	}
+	if !strings.Contains(err.Error(), "does not support PipelineRef or PipelineSpec") {
+		t.Errorf("Error getting tasks for fake pipeline %s: expected contains keyword but got %s", p.ObjectMeta.Name, err)
+	}
+}
+
 func TestResolvePipelineRun_TaskDoesntExist(t *testing.T) {
 	pts := []v1.PipelineTask{{
 		Name:    "mytask1",