diff --git a/CustomClusters/CustomClusters-1-0.6.ckan b/CustomClusters/CustomClusters-1-0.6.ckan
index 8c584fa422..4e0a54af49 100644
--- a/CustomClusters/CustomClusters-1-0.6.ckan
+++ b/CustomClusters/CustomClusters-1-0.6.ckan
@@ -1,5 +1,5 @@
 {
-    "spec_version": "v1.10",
+    "spec_version": "v1.4",
     "identifier": "CustomClusters",
     "name": "Custom Clusters by Vanguard Astrodynamics",
     "abstract": "More freedom in engine design",