diff --git a/src/Postmark/Postmark.csproj b/src/Postmark/Postmark.csproj
old mode 100755
new mode 100644
index 344f6d3..afa5fe5
--- a/src/Postmark/Postmark.csproj
+++ b/src/Postmark/Postmark.csproj
@@ -13,6 +13,6 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="10.0.3" />
-    <PackageReference Include="System.Net.Http" Version="4.3.3" />
+    <PackageReference Include="System.Net.Http" Version="4.3.4" />
   </ItemGroup>
 </Project>
\ No newline at end of file