diff --git a/package-lock.json b/package-lock.json
index 8abe8e3..6c6b9b2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1193,6 +1193,7 @@
           "version": "0.1.4",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "kind-of": "^3.0.2",
             "longest": "^1.0.1",
@@ -1517,7 +1518,8 @@
         "is-buffer": {
           "version": "1.1.6",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "is-builtin-module": {
           "version": "1.0.0",
@@ -1601,6 +1603,7 @@
           "version": "3.2.2",
           "bundled": true,
           "dev": true,
+          "optional": true,
           "requires": {
             "is-buffer": "^1.1.5"
           }
@@ -1647,7 +1650,8 @@
         "longest": {
           "version": "1.0.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "lru-cache": {
           "version": "4.1.3",
@@ -1913,7 +1917,8 @@
         "repeat-string": {
           "version": "1.6.1",
           "bundled": true,
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "require-directory": {
           "version": "2.1.1",
@@ -2563,9 +2568,9 @@
       }
     },
     "rollup": {
-      "version": "0.67.4",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.67.4.tgz",
-      "integrity": "sha512-AVuP73mkb4BBMUmksQ3Jw0jTrBTU1i7rLiUYjFxLZGb3xiFmtVEg40oByphkZAsiL0bJC3hRAJUQos/e5EBd+w==",
+      "version": "0.68.0",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.68.0.tgz",
+      "integrity": "sha512-UbmntCf8QBlOqJnwsNWQCI0oonHOgs9y1OLoO8BHf2r8gCyRLp3JzLHXARJpsNDAS08Qm3LDjzyWma5sqnCxDQ==",
       "dev": true,
       "requires": {
         "@types/estree": "0.0.39",
diff --git a/package.json b/package.json
index 5f6c218..f8d1f3e 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "jasmine-ts": "^0.3.0",
     "nyc": "^13.1.0",
     "rimraf": "^2.6.2",
-    "rollup": "^0.67.4",
+    "rollup": "^0.68.0",
     "rollup-plugin-uglify": "^6.0.0",
     "ts-node": "^7.0.1",
     "tslint": "^5.11.0",