diff --git a/package-lock.json b/package-lock.json
index 94a5731e..70a295c8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "configurable-http-proxy",
-  "version": "4.2.0",
+  "version": "4.2.1-dev",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -390,9 +390,9 @@
       }
     },
     "commander": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/commander/-/commander-4.0.0.tgz",
-      "integrity": "sha512-SEa2abMBTZuEjLVYpNrAFoRgxPwG4rXP3+SGY6CM/HZGeDzIA7Pzp+7H3AHDukKEpyy2SoSGGPShKqqfH9T9AQ=="
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-4.1.1.tgz",
+      "integrity": "sha512-NOKm8xhkzAjzFx8B2v5OAHT+u5pRQc2UCa2Vq9jYL/31o2wi9mxBA7LIFs3sV5VSC49z6pEhfbMULvShKj26WA=="
     },
     "commondir": {
       "version": "1.0.1",
diff --git a/package.json b/package.json
index 6abd3542..99cf65de 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "url": "https://github.com/jupyterhub/configurable-http-proxy.git"
   },
   "dependencies": {
-    "commander": "~4.0.0",
+    "commander": "~4.1.0",
     "http-proxy": "~1.18.0",
     "lynx": "^0.2.0",
     "strftime": "~0.10.0",