diff --git a/src/OrchardCore.Build/Dependencies.AspNetCore.props b/src/OrchardCore.Build/Dependencies.AspNetCore.props
index 76575d991e4..7201f3ea136 100644
--- a/src/OrchardCore.Build/Dependencies.AspNetCore.props
+++ b/src/OrchardCore.Build/Dependencies.AspNetCore.props
@@ -177,5 +177,14 @@
     <PackageManagement Include="Microsoft.VisualStudio.Web.CodeGenerators.Mvc" Version="2.2.0" />
     <PackageManagement Include="System.ComponentModel.Annotations" Version="4.5.0" />
     <PackageManagement Include="System.Security.Cryptography.Cng" Version="4.5.0" />
+
+    <!-- These definitions are are used in projects that incur package downgrades. -->
+    <PackageManagement Include="System.Collections" Version="4.3.0" />
+    <PackageManagement Include="System.Diagnostics.Debug" Version="4.3.0" />
+    <PackageManagement Include="System.Globalization" Version="4.3.0" />
+    <PackageManagement Include="System.IO" Version="4.3.0" />
+    <PackageManagement Include="System.IO.FileSystem.Primitives" Version="4.3.0" />
+    <PackageManagement Include="System.Net.Primitives" Version="4.3.0" />
+    <PackageManagement Include="System.Resources.ResourceManager" Version="4.3.0" />
   </ItemGroup>
 </Project>
diff --git a/src/OrchardCore/OrchardCore.Abstractions/OrchardCore.Abstractions.csproj b/src/OrchardCore/OrchardCore.Abstractions/OrchardCore.Abstractions.csproj
index 2023ab49938..485e88de71a 100644
--- a/src/OrchardCore/OrchardCore.Abstractions/OrchardCore.Abstractions.csproj
+++ b/src/OrchardCore/OrchardCore.Abstractions/OrchardCore.Abstractions.csproj
@@ -17,8 +17,6 @@
     <PackageReference Include="Microsoft.Extensions.Localization" />
     <PackageReference Include="Microsoft.Extensions.Logging" />
     <PackageReference Include="Newtonsoft.Json" />
-    <PackageReference Include="ncrontab" />
-    <PackageReference Include="NodaTime" />
   </ItemGroup>
 
 </Project>
diff --git a/src/OrchardCore/OrchardCore.Navigation.Core/OrchardCore.Navigation.Core.csproj b/src/OrchardCore/OrchardCore.Navigation.Core/OrchardCore.Navigation.Core.csproj
index 45d082646a6..22451ba3259 100644
--- a/src/OrchardCore/OrchardCore.Navigation.Core/OrchardCore.Navigation.Core.csproj
+++ b/src/OrchardCore/OrchardCore.Navigation.Core/OrchardCore.Navigation.Core.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
@@ -14,4 +14,8 @@
     <PackageReference Include="Microsoft.AspNetCore.Routing" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="System.IO.FileSystem.Primitives" />
+  </ItemGroup>
+
 </Project>
diff --git a/src/OrchardCore/OrchardCore.Abstractions/BackgroundTasks/BackgroundTaskScheduler.cs b/src/OrchardCore/OrchardCore/BackgroundTasks/BackgroundTaskScheduler.cs
similarity index 100%
rename from src/OrchardCore/OrchardCore.Abstractions/BackgroundTasks/BackgroundTaskScheduler.cs
rename to src/OrchardCore/OrchardCore/BackgroundTasks/BackgroundTaskScheduler.cs
diff --git a/src/OrchardCore/OrchardCore/OrchardCore.csproj b/src/OrchardCore/OrchardCore/OrchardCore.csproj
index 256606cd0ef..f5ee820c0df 100644
--- a/src/OrchardCore/OrchardCore/OrchardCore.csproj
+++ b/src/OrchardCore/OrchardCore/OrchardCore.csproj
@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
@@ -22,7 +22,10 @@
     <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" />
     <PackageReference Include="Microsoft.Extensions.Localization" />
     <PackageReference Include="Microsoft.Extensions.Logging" />
+    <PackageReference Include="ncrontab" />
     <PackageReference Include="NodaTime" />
+    
+    <!-- Remove this dependency in RC -->
     <PackageReference Include="YamlDotNet" />
   </ItemGroup>
 
@@ -30,4 +33,14 @@
     <ProjectReference Include="..\OrchardCore.Abstractions\OrchardCore.Abstractions.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <!-- Remove these references once ncrontab targets netstandard2.0-->
+    <PackageReference Include="System.Collections" />
+    <PackageReference Include="System.Diagnostics.Debug" />
+    <PackageReference Include="System.Globalization" />
+    <PackageReference Include="System.IO" />
+    <PackageReference Include="System.Net.Primitives" />
+    <PackageReference Include="System.Resources.ResourceManager" />
+  </ItemGroup>
+
 </Project>