diff --git a/hardware/unicorn/package.json b/hardware/unicorn/package.json
index 78af1a10..0c5ddbd9 100644
--- a/hardware/unicorn/package.json
+++ b/hardware/unicorn/package.json
@@ -3,7 +3,7 @@
     "version"       : "0.1.1",
     "description"   : "A Node-RED node to output to a Raspberry Pi Unicorn HAT from Pimorini.",
     "dependencies"  : {
-        "pngjs": "2.2.*"
+        "pngjs": "2.3.1"
     },
     "repository" : {
         "type":"git",