diff --git a/lib/bundler.js b/lib/bundler.js
index 1ebb323..e800589 100644
--- a/lib/bundler.js
+++ b/lib/bundler.js
@@ -120,8 +120,8 @@ function bundle(options) {
   });
 
   // A necessary code snippet so the Meteor client can work properly
-  var runtimeconfig = "__meteor_runtime_config__ = " +
-    JSON.stringify(config["runtime"], null, 2) + ";\n\n";
+  var runtimeconfig = "__meteor_runtime_config__ = Object.assign(" +
+    JSON.stringify(config["runtime"], null, 2) + ", window.__meteor_runtime_config__);\n\n";
 
   // In case we bundle into node_modules, ensue its existence
   if (!options.destination || config.generateNodeModules) {
diff --git a/package.json b/package.json
index 310096b..5ab6750 100644
--- a/package.json
+++ b/package.json
@@ -15,10 +15,10 @@
   },
   "dependencies": {
     "babel-core": "6.26.3",
-    "commander": "2.17.1",
+    "commander": "2.19.0",
     "execa": "1.0.0",
     "find-root": "1.1.0",
-    "merge": "1.2.0",
+    "merge": "1.2.1",
     "rimraf": "2.6.2",
     "tmp": "0.0.33"
   },
diff --git a/yarn.lock b/yarn.lock
index 42163a8..ef31c82 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -161,9 +161,9 @@ chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
-commander@2.17.1:
-  version "2.17.1"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-2.17.1.tgz#bd77ab7de6de94205ceacc72f1716d29f20a77bf"
+commander@2.19.0:
+  version "2.19.0"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.19.0.tgz#f6198aa84e5b83c46054b94ddedbfed5ee9ff12a"
 
 commander@2.9.0:
   version "2.9.0"
@@ -437,9 +437,9 @@ loose-envify@^1.0.0:
   dependencies:
     js-tokens "^3.0.0"
 
-merge@1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/merge/-/merge-1.2.0.tgz#7531e39d4949c281a66b8c5a6e0265e8b05894da"
+merge@1.2.1:
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/merge/-/merge-1.2.1.tgz#38bebf80c3220a8a487b6fcfb3941bb11720c145"
 
 minimatch@^3.0.2, minimatch@^3.0.4:
   version "3.0.4"