diff --git a/package.json b/package.json
index b5ad5cb..0945416 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "url": "https://github.com/KorAP/Kalamar.git"
   },
   "devDependencies": {
-    "grunt": "^1.0.4",
+    "grunt": "^1.5.3",
     "grunt-contrib-copy": "^1.0.0",
     "grunt-contrib-requirejs": "^1.0.0",
     "grunt-contrib-watch": "^1.1.0",
@@ -28,6 +28,7 @@
     "fsevents": "*"
   },
   "dependencies": {
-    "grunt-contrib-imagemin": "^4.0.0"
+    "grunt-contrib-imagemin": "^4.0.0",
+    "terser" : "^5.16.1"
   }
 }