diff --git a/library.json b/library.json
index 2c77bb5..70f49a2 100644
--- a/library.json
+++ b/library.json
@@ -7,6 +7,10 @@
   "runnable": 1,
   "author": "Oliver Tacke",
   "license": "MIT",
+  "coreApi": {
+    "majorVersion": 1,
+    "minorVersion": 27
+  },
   "machineName": "H5P.XRay",
   "embedTypes": [
     "iframe"