diff --git a/api.go b/api.go
index 79df0f28fc..0a7f7abea7 100644
--- a/api.go
+++ b/api.go
@@ -584,11 +584,7 @@ func postContainersRestart(srv *Server, version float64, w http.ResponseWriter,
 		return fmt.Errorf("Missing parameter")
 	}
 	job := srv.Eng.Job("restart", vars["name"])
-	if r.Form.Get("t") == "" {
-		job.Setenv("t", "-1")
-	} else {
-		job.Setenv("t", r.Form.Get("t"))
-	}
+	job.Setenv("t", r.Form.Get("t"))
 	if err := job.Run(); err != nil {
 		return err
 	}
@@ -656,11 +652,7 @@ func postContainersStop(srv *Server, version float64, w http.ResponseWriter, r *
 		return fmt.Errorf("Missing parameter")
 	}
 	job := srv.Eng.Job("stop", vars["name"])
-	if r.Form.Get("t") == "" {
-		job.Setenv("t", "-1")
-	} else {
-		job.Setenv("t", r.Form.Get("t"))
-	}
+	job.Setenv("t", r.Form.Get("t"))
 	if err := job.Run(); err != nil {
 		return err
 	}
diff --git a/engine/job.go b/engine/job.go
index 181eaa80c7..c2eadccc1b 100644
--- a/engine/job.go
+++ b/engine/job.go
@@ -102,6 +102,10 @@ func (job *Job) String() string {
 	return fmt.Sprintf("%s.%s%s", job.Eng, job.CallString(), job.StatusString())
 }
 
+func (job *Job) EnvExists(key string) (value bool) {
+	return job.env.Exists(key)
+}
+
 func (job *Job) Getenv(key string) (value string) {
 	return job.env.Get(key)
 }
diff --git a/server.go b/server.go
index 6291da6699..90a8bb3ed8 100644
--- a/server.go
+++ b/server.go
@@ -1798,10 +1798,12 @@ func (srv *Server) ContainerRestart(job *engine.Job) engine.Status {
 		job.Errorf("Usage: %s CONTAINER\n", job.Name)
 		return engine.StatusErr
 	}
-	name := job.Args[0]
-	t := job.GetenvInt("t")
-	if t == -1 {
-		t = 10
+	var (
+		name = job.Args[0]
+		t    = 10
+	)
+	if job.EnvExists("t") {
+		t = job.GetenvInt("t")
 	}
 	if container := srv.runtime.Get(name); container != nil {
 		if err := container.Restart(int(t)); err != nil {
@@ -2239,10 +2241,12 @@ func (srv *Server) ContainerStop(job *engine.Job) engine.Status {
 		job.Errorf("Usage: %s CONTAINER\n", job.Name)
 		return engine.StatusErr
 	}
-	name := job.Args[0]
-	t := job.GetenvInt("t")
-	if t == -1 {
-		t = 10
+	var (
+		name = job.Args[0]
+		t    = 10
+	)
+	if job.EnvExists("t") {
+		t = job.GetenvInt("t")
 	}
 	if container := srv.runtime.Get(name); container != nil {
 		if err := container.Stop(int(t)); err != nil {