diff --git a/package-lock.json b/package-lock.json
index 795bbc9..280537a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -127,7 +127,8 @@
       "version": "2.7.0",
       "resolved": "https://registry.npmjs.org/acorn/-/acorn-2.7.0.tgz",
       "integrity": "sha1-q259nYhqrKiwhbwzEreaGYQz8Oc=",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "acorn-globals": {
       "version": "1.0.9",
@@ -612,7 +613,8 @@
       "version": "0.3.6",
       "resolved": "https://registry.npmjs.org/cssom/-/cssom-0.3.6.tgz",
       "integrity": "sha512-DtUeseGk9/GBW0hl0vVPpU22iHL6YB5BUX7ml1hB+GMpo0NX5G4voX3kdWiMSEguFtcW3Vh3djqNF4aIe6ne0A==",
-      "dev": true
+      "dev": true,
+      "optional": true
     },
     "cssstyle": {
       "version": "0.2.37",
@@ -3240,9 +3242,9 @@
       "dev": true
     },
     "underscore": {
-      "version": "1.9.1",
-      "resolved": "https://registry.npmjs.org/underscore/-/underscore-1.9.1.tgz",
-      "integrity": "sha512-5/4etnCkd9c8gwgowi5/om/mYO5ajCaOgdzj/oW+0eQV9WxKBDZw5+ycmKmeaTXjInS/W0BzpGLo2xR2aBwZdg=="
+      "version": "1.13.1",
+      "resolved": "https://registry.npmjs.org/underscore/-/underscore-1.13.1.tgz",
+      "integrity": "sha512-hzSoAVtJF+3ZtiFX0VgfFPHEDRm7Y/QPjGyNo4TVdnDTdft3tr8hEkD25a1jC+TjTuE7tkHGKkhwCgs9dgBB2g=="
     },
     "universalify": {
       "version": "0.1.2",