diff --git a/package.json b/package.json
index bfe28de..bacf810 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
     "grunt-shell": "^4.0.0",
     "grunt-terser": "^1.0.0",
     "imagemin": "^8.0.1",
-    "optipng-bin": "^6.0.0",
+    "optipng-bin": "^9.0.0",
     "sass": "^1.44.0",
     "vinyl-fs": "^3.0.3"
   },