diff --git a/package.json b/package.json
index 9450c86e..672636be 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,7 @@
     "jszip": "3.1.5",
     "normalize.css": "7.0.0",
     "nprogress": "0.2.0",
+    "path-to-regexp": "^2.4.0",
     "screenfull": "3.3.3",
     "showdown": "1.8.6",
     "simplemde": "1.11.2",