diff --git a/pkg/genericapiserver/default_storage_factory_builder.go b/pkg/genericapiserver/default_storage_factory_builder.go
index 8219f1525e2..63a26ccf30c 100644
--- a/pkg/genericapiserver/default_storage_factory_builder.go
+++ b/pkg/genericapiserver/default_storage_factory_builder.go
@@ -70,12 +70,12 @@ func mergeAPIResourceConfigs(defaultAPIResourceConfig *ResourceConfig, resourceC
 
 	// "api/all=false" allows users to selectively enable specific api versions.
 	allAPIFlagValue, ok := overrides["api/all"]
-	if ok && allAPIFlagValue == "false" {
-		// Disable all group versions.
-		for _, groupVersion := range registered.RegisteredGroupVersions() {
-			if resourceConfig.AnyResourcesForVersionEnabled(groupVersion) {
-				resourceConfig.DisableVersions(groupVersion)
-			}
+	if ok {
+		if allAPIFlagValue == "false" {
+			// Disable all group versions.
+			resourceConfig.DisableVersions(registered.RegisteredGroupVersions()...)
+		} else if allAPIFlagValue == "true" {
+			resourceConfig.EnableVersions(registered.RegisteredGroupVersions()...)
 		}
 	}
 
diff --git a/pkg/genericapiserver/default_storage_factory_builder_test.go b/pkg/genericapiserver/default_storage_factory_builder_test.go
index 447778ebc3b..f17324bad37 100644
--- a/pkg/genericapiserver/default_storage_factory_builder_test.go
+++ b/pkg/genericapiserver/default_storage_factory_builder_test.go
@@ -22,6 +22,7 @@ import (
 
 	"k8s.io/kubernetes/pkg/api/unversioned"
 	apiv1 "k8s.io/kubernetes/pkg/api/v1"
+	"k8s.io/kubernetes/pkg/apimachinery/registered"
 	extensionsapiv1beta1 "k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
 )
 
@@ -159,6 +160,36 @@ func TestParseRuntimeConfig(t *testing.T) {
 			},
 			err: true,
 		},
+		{
+			// enable all
+			runtimeConfig: map[string]string{
+				"api/all": "true",
+			},
+			defaultResourceConfig: func() *ResourceConfig {
+				return NewResourceConfig()
+			},
+			expectedAPIConfig: func() *ResourceConfig {
+				config := NewResourceConfig()
+				config.EnableVersions(registered.RegisteredGroupVersions()...)
+				return config
+			},
+			err: false,
+		},
+		{
+			// disable all
+			runtimeConfig: map[string]string{
+				"api/all": "false",
+			},
+			defaultResourceConfig: func() *ResourceConfig {
+				return NewResourceConfig()
+			},
+			expectedAPIConfig: func() *ResourceConfig {
+				config := NewResourceConfig()
+				config.DisableVersions(registered.RegisteredGroupVersions()...)
+				return config
+			},
+			err: false,
+		},
 	}
 	for _, test := range testCases {
 		actualDisablers, err := mergeAPIResourceConfigs(test.defaultResourceConfig(), test.runtimeConfig)
@@ -173,5 +204,4 @@ func TestParseRuntimeConfig(t *testing.T) {
 			t.Fatalf("%v: unexpected apiResourceDisablers. Actual: %v\n expected: %v", test.runtimeConfig, actualDisablers, expectedConfig)
 		}
 	}
-
 }