diff --git a/pkg/acsengine/defaults.go b/pkg/acsengine/defaults.go
index 3d2fd21cc1..0460f972c7 100644
--- a/pkg/acsengine/defaults.go
+++ b/pkg/acsengine/defaults.go
@@ -720,6 +720,9 @@ func getAddonContainersIndexByName(containers []api.KubernetesContainerSpec, nam
 
 // assignDefaultAddonVals will assign default values to addon from defaults, for each property in addon that has a zero value
 func assignDefaultAddonVals(addon, defaults api.KubernetesAddon) api.KubernetesAddon {
+	if addon.Enabled == nil {
+		addon.Enabled = defaults.Enabled
+	}
 	for i := range defaults.Containers {
 		c := getAddonContainersIndexByName(addon.Containers, defaults.Containers[i].Name)
 		if c < 0 {