diff --git a/routers/user/setting/account.go b/routers/user/setting/account.go
index 27f0bf1c8..6165bfc5b 100644
--- a/routers/user/setting/account.go
+++ b/routers/user/setting/account.go
@@ -80,6 +80,12 @@ func EmailPost(ctx *context.Context, form auth.AddEmailForm) {
 	// Make emailaddress primary.
 	if ctx.Query("_method") == "PRIMARY" {
 		if err := models.MakeEmailPrimary(&models.EmailAddress{ID: ctx.QueryInt64("id")}); err != nil {
+			if _, ok := err.(models.ErrEmailAlreadyUsed); ok {
+				ctx.Flash.Error(ctx.Tr("form.email_been_used"))
+				ctx.Redirect(setting.AppSubURL + "/user/settings/account")
+				return
+			}
+
 			ctx.ServerError("MakeEmailPrimary", err)
 			return
 		}