diff --git a/lib/shared.js b/lib/shared.js
index 1a12276..dddea59 100644
--- a/lib/shared.js
+++ b/lib/shared.js
@@ -43,7 +43,7 @@ try {
   opts = ini.parse(fs.readFileSync('./.screepsrc', {encoding: 'utf8'}))
 } catch (e) {}
 opts.history = opts.history || {}
-Object.assign(opts.history, DEFAULTS, opts.history, ENV)
+opts.history = Object.assign({}, DEFAULTS, opts.history, ENV)
 
 class FileAdapter {
   constructor (opts) {