diff --git a/system.json b/system.json
index 75608fc..dba6737 100644
--- a/system.json
+++ b/system.json
@@ -18,7 +18,8 @@
   "version": "1.3.5",
   "compatibility": {
     "minimum": "11",
-    "verified": "11"
+    "verified": "12",
+    "maximum": "12"
   },
   "esmodules": ["module/deltagreen.js"],
   "styles": ["css/deltagreen.css", "css/dialogue.css"],