diff --git a/src/models/layerMetadata/decorators/property/tsTypes.decorator.ts b/src/models/layerMetadata/decorators/property/tsTypes.decorator.ts
index bb24a53..741ce04 100644
--- a/src/models/layerMetadata/decorators/property/tsTypes.decorator.ts
+++ b/src/models/layerMetadata/decorators/property/tsTypes.decorator.ts
@@ -26,6 +26,10 @@ export const TsTypes: Record<string, IDescribeTsType> = {
     value: 'string',
     type: PropertiesTypes.ARRAY,
   },
+  NULLABLE_STRING: {
+    value: 'string | null',
+    type: PropertiesTypes.PRIMITIVE,
+  },
   BOOLEAN: {
     value: 'boolean',
     type: PropertiesTypes.PRIMITIVE,
diff --git a/src/models/layerMetadata/pycswLayerCatalogRecord.ts b/src/models/layerMetadata/pycswLayerCatalogRecord.ts
index 0065cf5..951d54d 100644
--- a/src/models/layerMetadata/pycswLayerCatalogRecord.ts
+++ b/src/models/layerMetadata/pycswLayerCatalogRecord.ts
@@ -34,7 +34,7 @@ export class PycswLayerCatalogRecord extends LayerMetadata implements IPycswCore
     },
   })
   @tsTypes({
-    mappingType: TsTypes.STRING,
+    mappingType: TsTypes.NULLABLE_STRING,
   })
   @graphql()
   @fieldConfig({