diff --git a/Tests/Tests.csproj b/Tests/Tests.csproj
index d309bb1..55daedf 100644
--- a/Tests/Tests.csproj
+++ b/Tests/Tests.csproj
@@ -10,7 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Hl7.Fhir.STU3" Version="1.2.1" />
-    <PackageReference Include="Microsoft.AspNetCore.App" Version="2.1.5" />
+    <PackageReference Include="Microsoft.AspNetCore.App" Version="2.1.15" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="2.1.3" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
     <PackageReference Include="xunit" Version="2.4.1" />