diff --git a/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN.Abp.EventBus.CAP.csproj b/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN.Abp.EventBus.CAP.csproj
index 31697d04e..9efab005a 100644
--- a/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN.Abp.EventBus.CAP.csproj
+++ b/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN.Abp.EventBus.CAP.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\..\common.props" />
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>netstandard2.1</TargetFramework>
     <RootNamespace />
     <Description>Cap分布式事件总线</Description>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="DotNetCore.CAP" Version="3.1.2" />
+    <PackageReference Include="DotNetCore.CAP" Version="5.0.2" />
     <PackageReference Include="Volo.Abp.BackgroundWorkers" Version="4.3.0" />
     <PackageReference Include="Volo.Abp.EventBus" Version="4.3.0" />
   </ItemGroup>
diff --git a/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN/Abp/EventBus/CAP/AbpCAPMessageExtensions.cs b/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN/Abp/EventBus/CAP/AbpCAPMessageExtensions.cs
index 08e770bcd..6c563caa0 100644
--- a/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN/Abp/EventBus/CAP/AbpCAPMessageExtensions.cs
+++ b/aspnet-core/modules/common/LINGYUN.Abp.EventBus.CAP/LINGYUN/Abp/EventBus/CAP/AbpCAPMessageExtensions.cs
@@ -16,16 +16,17 @@ namespace LINGYUN.Abp.EventBus.CAP
         /// <returns></returns>
         public static bool TryGetTenantId(
             this Message message,
-            out Guid tenantId)
+            out Guid? tenantId)
         {
             if (message.Headers.TryGetValue(AbpCAPHeaders.TenantId, out string tenantStr))
             {
-                if (Guid.TryParse(tenantStr, out tenantId))
+                if (Guid.TryParse(tenantStr, out Guid id))
                 {
+                    tenantId = id;
                     return true;
                 }
             }
-
+            tenantId = null;
             return false;
         }
         /// <summary>
@@ -36,7 +37,7 @@ namespace LINGYUN.Abp.EventBus.CAP
         public static Guid? GetTenantIdOrNull(
             this Message message)
         {
-            if (message.TryGetTenantId(out Guid tenantId))
+            if (message.TryGetTenantId(out Guid? tenantId))
             {
                 return tenantId;
             }