diff --git a/pkg/cmd/server/start/start_kube_controller_manager.go b/pkg/cmd/server/start/start_kube_controller_manager.go
index f45e70a1f997..31be0e3399f0 100644
--- a/pkg/cmd/server/start/start_kube_controller_manager.go
+++ b/pkg/cmd/server/start/start_kube_controller_manager.go
@@ -217,7 +217,7 @@ func createRecylerTemplate(recyclerImage string) (string, error) {
 }
 
 func runEmbeddedKubeControllerManager(kubeconfigFile, saPrivateKeyFile, saRootCAFile, podEvictionTimeout string, dynamicProvisioningEnabled bool, cmdLineArgs map[string][]string,
-	recyclerImage string, informers *informers) {
+	initialized chan struct{}, recyclerImage string, informers *informers) {
 	controllerapp.CreateControllerContext = newKubeControllerContext(informers)
 	controllerapp.StartInformers = func(stop <-chan struct{}) {
 		informers.Start(stop)
@@ -233,6 +233,9 @@ func runEmbeddedKubeControllerManager(kubeconfigFile, saPrivateKeyFile, saRootCA
 			f()
 		}
 	}()
+	// At this point do not mutate cmdLineArgs and signal this back to upper
+	// level.
+	close(initialized)
 
 	if err != nil {
 		glog.Fatal(err)
diff --git a/pkg/cmd/server/start/start_master.go b/pkg/cmd/server/start/start_master.go
index 387b39a94e16..9690ef5f2ee0 100644
--- a/pkg/cmd/server/start/start_master.go
+++ b/pkg/cmd/server/start/start_master.go
@@ -475,6 +475,8 @@ func (m *Master) Start() error {
 			// continuously run the scheduler while we have the primary lease
 			go runEmbeddedScheduler(m.config.MasterClients.OpenShiftLoopbackKubeConfig, m.config.KubernetesMasterConfig.SchedulerConfigFile, m.config.KubernetesMasterConfig.SchedulerArguments)
 
+			controllerArgumentsInitialized := make(chan struct{})
+
 			go runEmbeddedKubeControllerManager(
 				m.config.MasterClients.OpenShiftLoopbackKubeConfig,
 				m.config.ServiceAccountConfig.PrivateKeyFile,
@@ -482,9 +484,14 @@ func (m *Master) Start() error {
 				m.config.KubernetesMasterConfig.PodEvictionTimeout,
 				m.config.VolumeConfig.DynamicProvisioningEnabled,
 				m.config.KubernetesMasterConfig.ControllerArguments,
+				controllerArgumentsInitialized,
 				recyclerImage,
 				informers)
 
+			// Wait for the runEmbeddedKubeControllerManager to mutate the
+			// ControllerArguments to prevent getOpenshiftControllerOptions from
+			// panicking because of concurrent read/write access.
+			<-controllerArgumentsInitialized
 			openshiftControllerOptions, err := getOpenshiftControllerOptions(m.config.KubernetesMasterConfig.ControllerArguments)
 			if err != nil {
 				glog.Fatal(err)