diff --git a/pkg/app/piped/executor/waitapproval/waitapproval.go b/pkg/app/piped/executor/waitapproval/waitapproval.go
index 3ec1c0f976..f2f4e0b908 100644
--- a/pkg/app/piped/executor/waitapproval/waitapproval.go
+++ b/pkg/app/piped/executor/waitapproval/waitapproval.go
@@ -55,6 +55,8 @@ func (e *Executor) Execute(sig executor.StopSignal) model.StageStatus {
 	)
 	defer ticker.Stop()
 
+	timer := time.NewTimer(time.Duration(e.StageConfig.WaitApprovalStageOptions.Timeout) * time.Second)
+
 	e.LogPersister.Info("Waiting for an approval...")
 	for {
 		select {
@@ -73,6 +75,9 @@ func (e *Executor) Execute(sig executor.StopSignal) model.StageStatus {
 			default:
 				return model.StageStatus_STAGE_FAILURE
 			}
+		case <-timer.C:
+			e.LogPersister.Errorf("Timed out %v", e.StageConfig.WaitApprovalStageOptions.Timeout)
+			return model.StageStatus_STAGE_FAILURE
 		}
 	}
 }
diff --git a/pkg/config/deployment.go b/pkg/config/deployment.go
index 813007d02b..b281c27147 100644
--- a/pkg/config/deployment.go
+++ b/pkg/config/deployment.go
@@ -17,10 +17,13 @@ package config
 import (
 	"encoding/json"
 	"fmt"
+	"time"
 
 	"github.com/pipe-cd/pipe/pkg/model"
 )
 
+var defaultWaitApprovalTimeout = Duration(6 * time.Hour)
+
 type GenericDeploymentSpec struct {
 	// Forcibly use QuickSync or Pipeline when commit message matched the specified pattern.
 	CommitMatcher DeploymentCommitMatcher `json:"commitMatcher"`
@@ -66,13 +69,13 @@ type DeploymentCommitMatcher struct {
 
 // DeploymentPipeline represents the way to deploy the application.
 // The pipeline is triggered by changes in any of the following objects:
-// - Target PodSpec (Target can be Deployment, DaemonSet, StatefullSet)
+// - Target PodSpec (Target can be Deployment, DaemonSet, StatefulSet)
 // - ConfigMaps, Secrets that are mounted as volumes or envs in the deployment.
 type DeploymentPipeline struct {
 	Stages []PipelineStage `json:"stages"`
 }
 
-// PiplineStage represents a single stage of a pipeline.
+// PipelineStage represents a single stage of a pipeline.
 // This is used as a generic struct for all stage type.
 type PipelineStage struct {
 	Id      string
@@ -133,6 +136,9 @@ func (s *PipelineStage) UnmarshalJSON(data []byte) error {
 		if len(gs.With) > 0 {
 			err = json.Unmarshal(gs.With, s.WaitApprovalStageOptions)
 		}
+		if s.WaitApprovalStageOptions.Timeout <= 0 {
+			s.WaitApprovalStageOptions.Timeout = defaultWaitApprovalTimeout
+		}
 	case model.StageAnalysis:
 		s.AnalysisStageOptions = &AnalysisStageOptions{}
 		if len(gs.With) > 0 {
@@ -220,6 +226,8 @@ type WaitStageOptions struct {
 
 // WaitStageOptions contains all configurable values for a WAIT_APPROVAL stage.
 type WaitApprovalStageOptions struct {
+	// The maximum length of time to wait before giving up.
+	Timeout   Duration `json:"timeout"`
 	Approvers []string `json:"approvers"`
 }
 
diff --git a/pkg/config/deployment_terraform_test.go b/pkg/config/deployment_terraform_test.go
index 2b63cb7a72..24a4c715dd 100644
--- a/pkg/config/deployment_terraform_test.go
+++ b/pkg/config/deployment_terraform_test.go
@@ -90,6 +90,8 @@ func TestTerraformDeploymentConfig(t *testing.T) {
 								Name: model.StageWaitApproval,
 								WaitApprovalStageOptions: &WaitApprovalStageOptions{
 									Approvers: []string{"foo", "bar"},
+									// Use defaultWaitApprovalTimeout on unset timeout value for WaitApprovalStage.
+									Timeout: defaultWaitApprovalTimeout,
 								},
 							},
 							{