diff --git a/common/script/ops/unlock.js b/common/script/ops/unlock.js
index 5e0b118af0..5a53965443 100644
--- a/common/script/ops/unlock.js
+++ b/common/script/ops/unlock.js
@@ -5,6 +5,7 @@ import {
   NotAuthorized,
   BadRequest,
 } from '../libs/errors';
+import setWith from 'lodash.setwith'; // Not available in lodash 3
 
 // If item is already purchased -> equip it
 // Otherwise unlock it
@@ -60,10 +61,12 @@ module.exports = function unlock (user, req = {}, analytics) {
   if (isFullSet) {
     _.each(setPaths, function markItemsAsPurchased (pathPart) {
       if (path.indexOf('gear.') !== -1) {
-        _.set(user, pathPart, true);
+        // Using Object so path[1] won't create an array but an object {path: {1: value}}
+        setWith(user, pathPart, true);
       }
 
-      _.set(user, `purchased.${pathPart}`, true);
+      // Using Object so path[1] won't create an array but an object {path: {1: value}}
+      setWith(user, `purchased.${pathPart}`, true, Object);
     });
   } else {
     if (alreadyOwns) { // eslint-disable-line no-lonely-if
@@ -74,9 +77,11 @@ module.exports = function unlock (user, req = {}, analytics) {
         value = '';
       }
 
-      _.set(user, `preferences.${key}`, value);
+      // Using Object so path[1] won't create an array but an object {path: {1: value}}
+      setWith(user, `preferences.${key}`, value);
     } else {
-      _.set(user, `purchased.${path}`, true);
+      // Using Object so path[1] won't create an array but an object {path: {1: value}}
+      setWith(user, `purchased.${path}`, true, Object);
     }
   }
 
diff --git a/package.json b/package.json
index fa12cb4dbb..b238a16977 100644
--- a/package.json
+++ b/package.json
@@ -58,6 +58,7 @@
     "jade": "~1.11.0",
     "js2xmlparser": "~1.0.0",
     "lodash": "^3.10.1",
+    "lodash.setwith": "^4.2.0",
     "loggly": "~1.0.8",
     "markdown-it": "^6.0.1",
     "merge-stream": "^1.0.0",