diff --git a/framework/src/Volo.Abp.AspNetCore.Components.Web.Theming/Bundling/AbpStyles.razor b/framework/src/Volo.Abp.AspNetCore.Components.Web.Theming/Bundling/AbpStyles.razor
index 053e0efd01..bae9b382f3 100644
--- a/framework/src/Volo.Abp.AspNetCore.Components.Web.Theming/Bundling/AbpStyles.razor
+++ b/framework/src/Volo.Abp.AspNetCore.Components.Web.Theming/Bundling/AbpStyles.razor
@@ -42,7 +42,7 @@
 
         if (OperatingSystem.IsBrowser() && WebAssemblyStyleFiles != null)
         {
-            StyleFiles!.AddRange(WebAssemblyStyleFiles);
+            StyleFiles?.AddRange(WebAssemblyStyleFiles);
         }
     }