diff --git a/Service/Service.csproj b/Service/Service.csproj
index e964686..b4cce1f 100644
--- a/Service/Service.csproj
+++ b/Service/Service.csproj
@@ -14,7 +14,7 @@
         <PackageReference Include="DotNetty.Handlers" Version="0.7.5" />
         <PackageReference Include="DotNetty.Transport" Version="0.7.5" />
         <PackageReference Include="log4net" Version="2.0.15" />
-        <PackageReference Include="MQTTnet.AspNetCore" Version="4.3.5.1141" />
+        <PackageReference Include="MQTTnet.AspNetCore" Version="3.1.2" />
         <PackageReference Include="SqlSugarCore" Version="5.1.4.115" />
         <PackageReference Include="DotNetty.Buffers" Version="0.7.5"/>
         <PackageReference Include="DotNetty.Codecs" Version="0.7.5"/>