diff --git a/package.json b/package.json
index 83e27234793..a9c69e2a40b 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,7 @@
     "ncp": "^2.0.0",
     "pdfjs-dist": "^1.8.595",
     "pixelmatch": "^4.0.2",
-    "pngjs": "^3.2.0",
+    "pngjs": "^3.3.3",
     "text-diff": "^1.0.1",
     "typescript": "~2.8.1"
   }