diff --git a/src/Models/ThemeConfig/Conversion/PrevalidateLayer.ts b/src/Models/ThemeConfig/Conversion/PrevalidateLayer.ts
index 5412fe52e..6707194b0 100644
--- a/src/Models/ThemeConfig/Conversion/PrevalidateLayer.ts
+++ b/src/Models/ThemeConfig/Conversion/PrevalidateLayer.ts
@@ -141,7 +141,7 @@ export class PrevalidateLayer extends DesugaringStep<LayerConfigJson> {
             }
         }
 
-        if(json.allowMove === undefined && json.source["geoJson"] === undefined){
+        if(this._isBuiltin && json.allowMove === undefined && json.source["geoJson"] === undefined){
             if (!Constants.priviliged_layers.find((x) => x == json.id)) {
                 context.err(
                     "Layer " +