diff --git a/src/ElasticSearch.Extensions.Logging/AM.Extensions.Logging.ElasticSearch.csproj b/src/ElasticSearch.Extensions.Logging/AM.Extensions.Logging.ElasticSearch.csproj
index b00fe12..ee0fd81 100644
--- a/src/ElasticSearch.Extensions.Logging/AM.Extensions.Logging.ElasticSearch.csproj
+++ b/src/ElasticSearch.Extensions.Logging/AM.Extensions.Logging.ElasticSearch.csproj
@@ -22,7 +22,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.2" />
-    <PackageReference Include="System.Reactive.Linq" Version="3.1.1" />
+    <PackageReference Include="System.Reactive.Linq" Version="4.0.0" />
   </ItemGroup>
 
 </Project>