diff --git a/cmd/controller/app/controller.go b/cmd/controller/app/controller.go
index aad96e829..14f6c2d01 100644
--- a/cmd/controller/app/controller.go
+++ b/cmd/controller/app/controller.go
@@ -28,7 +28,11 @@ import (
 	kubeinformers "k8s.io/client-go/informers"
 )
 
-const controllerAgentName = "cert-manager-controller"
+const (
+	controllerAgentName = "cert-manager-controller"
+
+	defaultNamespace = ""
+)
 
 func Run(opts *options.ControllerOptions, stopCh <-chan struct{}) {
 	ctx, kubeCfg, err := buildControllerContext(opts)
@@ -120,8 +124,8 @@ func buildControllerContext(opts *options.ControllerOptions) (*controller.Contex
 	// If it is specified, all operations relating to ClusterIssuer resources
 	// should be disabled and thus we don't need to also create factories for
 	// the --cluster-resource-namespace.
-	sharedInformerFactory := informers.NewFilteredSharedInformerFactory(intcl, time.Second*30, opts.Namespace, nil)
-	kubeSharedInformerFactory := kubeinformers.NewFilteredSharedInformerFactory(cl, time.Second*30, opts.Namespace, nil)
+	sharedInformerFactory := informers.NewFilteredSharedInformerFactory(intcl, time.Second*30, defaultNamespace, nil)
+	kubeSharedInformerFactory := kubeinformers.NewFilteredSharedInformerFactory(cl, time.Second*30, defaultNamespace, nil)
 	return &controller.Context{
 		Client:                    cl,
 		CMClient:                  intcl,
@@ -134,13 +138,13 @@ func buildControllerContext(opts *options.ControllerOptions) (*controller.Contex
 			Recorder:                        recorder,
 			KubeSharedInformerFactory:       kubeSharedInformerFactory,
 			SharedInformerFactory:           sharedInformerFactory,
-			Namespace:                       opts.Namespace,
+			Namespace:                       defaultNamespace,
 			ClusterResourceNamespace:        opts.ClusterResourceNamespace,
 			ACMEHTTP01SolverImage:           opts.ACMEHTTP01SolverImage,
 			ClusterIssuerAmbientCredentials: opts.ClusterIssuerAmbientCredentials,
 			IssuerAmbientCredentials:        opts.IssuerAmbientCredentials,
 		}),
-		Namespace:                opts.Namespace,
+		Namespace:                defaultNamespace,
 		ClusterResourceNamespace: opts.ClusterResourceNamespace,
 	}, kubeCfg, nil
 }
diff --git a/cmd/controller/app/options/options.go b/cmd/controller/app/options/options.go
index eabf792bf..8c37d5163 100644
--- a/cmd/controller/app/options/options.go
+++ b/cmd/controller/app/options/options.go
@@ -11,7 +11,6 @@ import (
 
 type ControllerOptions struct {
 	APIServerHost            string
-	Namespace                string
 	ClusterResourceNamespace string
 
 	LeaderElect                 bool
@@ -28,7 +27,6 @@ type ControllerOptions struct {
 
 const (
 	defaultAPIServerHost            = ""
-	defaultNamespace                = ""
 	defaultClusterResourceNamespace = "kube-system"
 
 	defaultLeaderElect                 = true
@@ -48,7 +46,6 @@ var (
 func NewControllerOptions() *ControllerOptions {
 	return &ControllerOptions{
 		APIServerHost:                   defaultAPIServerHost,
-		Namespace:                       defaultNamespace,
 		ClusterResourceNamespace:        defaultClusterResourceNamespace,
 		LeaderElect:                     defaultLeaderElect,
 		LeaderElectionNamespace:         defaultLeaderElectionNamespace,
@@ -64,13 +61,9 @@ func (s *ControllerOptions) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.APIServerHost, "master", defaultAPIServerHost, ""+
 		"Optional apiserver host address to connect to. If not specified, autoconfiguration "+
 		"will be attempted.")
-	fs.StringVar(&s.Namespace, "namespace", defaultNamespace, ""+
-		"Optional namespace to monitor resources within. This can be used to limit the scope "+
-		"of cert-manager to a single namespace. If not specified, all namespaces will be watched")
 	fs.StringVar(&s.ClusterResourceNamespace, "cluster-resource-namespace", defaultClusterResourceNamespace, ""+
 		"Namespace to store resources owned by cluster scoped resources such as ClusterIssuer in. "+
 		"This must be specified if ClusterIssuers are enabled.")
-
 	fs.BoolVar(&s.LeaderElect, "leader-elect", true, ""+
 		"If true, cert-manager will perform leader election between instances to ensure no more "+
 		"than one instance of cert-manager operates at a time")