diff --git a/package-lock.json b/package-lock.json
index 78b2469..cddbdf0 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -657,7 +657,8 @@
     "console-control-strings": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/console-control-strings/-/console-control-strings-1.1.0.tgz",
-      "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4="
+      "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4=",
+      "optional": true
     },
     "core-js": {
       "version": "2.5.1",
@@ -1152,6 +1153,7 @@
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/fstream/-/fstream-1.0.11.tgz",
       "integrity": "sha1-XB+x8RdHcRTwYyoOtLcbPLD9MXE=",
+      "optional": true,
       "requires": {
         "graceful-fs": "4.1.11",
         "inherits": "2.0.3",