diff --git a/Models/ThemeConfig/Conversion/LegacyJsonConvert.ts b/Models/ThemeConfig/Conversion/LegacyJsonConvert.ts
index 547f8c57b..5d9ae5862 100644
--- a/Models/ThemeConfig/Conversion/LegacyJsonConvert.ts
+++ b/Models/ThemeConfig/Conversion/LegacyJsonConvert.ts
@@ -18,10 +18,12 @@ export class UpdateLegacyLayer extends DesugaringStep<LayerConfigJson | string |
             // Reuse of an already existing layer; return as-is
             return {result: json, errors: [], warnings: []}
         }
-        let config: any = {...json};
+        let config  = {...json};
 
         if (config["overpassTags"]) {
-            config.source = config.source ?? {}
+            config.source = config.source ?? {
+                osmTags: config["overpassTags"]
+            }
             config.source.osmTags = config["overpassTags"]
             delete config["overpassTags"]
         }