diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/ResolveAssemblies.cs b/src/Xamarin.Android.Build.Tasks/Tasks/ResolveAssemblies.cs
index 420a38a12fb..108c7922d49 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/ResolveAssemblies.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/ResolveAssemblies.cs
@@ -23,6 +23,8 @@ public class ResolveAssemblies : Task
 		[Required]
 		public string ReferenceAssembliesDirectory { get; set; }
 
+		public ITaskItem[] DesignTimeFacadeDirectories { get; set; }
+
 		public string I18nAssemblies { get; set; }
 		public string LinkMode { get; set; }
 
@@ -56,11 +58,12 @@ bool Execute (DirectoryAssemblyResolver resolver)
 			Log.LogDebugMessage ("  I18nAssemblies: {0}", I18nAssemblies);
 			Log.LogDebugMessage ("  LinkMode: {0}", LinkMode);
 			Log.LogDebugTaskItems ("  Assemblies:", Assemblies);
+			Log.LogDebugTaskItems ("  DesignTimeFacadeDirectories:", DesignTimeFacadeDirectories);
 
 			foreach (var dir in ReferenceAssembliesDirectory.Split (new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries))
 				resolver.SearchDirectories.Add (dir);
 
-			var assemblies = new HashSet<string> ();
+			var assemblies = new HashSet<ITaskItem> (new ITaskItemEqualityComparer ());
 
 			var topAssemblyReferences = new List<AssemblyDefinition> ();
 
@@ -76,7 +79,7 @@ bool Execute (DirectoryAssemblyResolver resolver)
 					if (assemblyDef == null)
 						throw new InvalidOperationException ("Failed to load assembly " + assembly.ItemSpec);
 					topAssemblyReferences.Add (assemblyDef);
-					assemblies.Add (Path.GetFullPath (assemblyDef.MainModule.FullyQualifiedName));
+					assemblies.Add (new TaskItem (Path.GetFullPath (assemblyDef.MainModule.FullyQualifiedName)));
 				}
 			} catch (Exception ex) {
 				Log.LogError ("Exception while loading assemblies: {0}", ex);
@@ -93,8 +96,8 @@ bool Execute (DirectoryAssemblyResolver resolver)
 			// Add I18N assemblies if needed
 			AddI18nAssemblies (resolver, assemblies);
 
-			ResolvedAssemblies = assemblies.Select (a => new TaskItem (a)).ToArray ();
-			ResolvedSymbols = assemblies.Select (a => a + ".mdb").Where (a => File.Exists (a)).Select (a => new TaskItem (a)).ToArray ();
+			ResolvedAssemblies = assemblies.ToArray ();
+			ResolvedSymbols = assemblies.Select (a => new TaskItem (a + ".mdb")).Where (a => File.Exists (a.ItemSpec)).ToArray ();
 			ResolvedFrameworkAssemblies = ResolvedAssemblies.Where (p => MonoAndroidHelper.IsFrameworkAssembly (p.ItemSpec, true)).ToArray ();
 			ResolvedUserAssemblies = ResolvedAssemblies.Where (p => !MonoAndroidHelper.IsFrameworkAssembly (p.ItemSpec, true)).ToArray ();
 			ResolvedDoNotPackageAttributes = do_not_package_atts.ToArray ();
@@ -110,13 +113,14 @@ bool Execute (DirectoryAssemblyResolver resolver)
 		readonly List<string> do_not_package_atts = new List<string> ();
 		int indent = 2;
 
-		void AddAssemblyReferences (DirectoryAssemblyResolver resolver, ICollection<string> assemblies, AssemblyDefinition assembly, bool topLevel)
+		void AddAssemblyReferences (DirectoryAssemblyResolver resolver, ICollection<ITaskItem> assemblies, AssemblyDefinition assembly, bool topLevel)
 		{
 			var fqname = assembly.MainModule.FullyQualifiedName;
 			var fullPath = Path.GetFullPath (fqname);
+			var item = new TaskItem (fullPath);
 
 			// Don't repeat assemblies we've already done
-			if (!topLevel && assemblies.Contains (fullPath))
+			if (!topLevel && assemblies.Contains (item))
 				return;
 			
 			foreach (var att in assembly.CustomAttributes.Where (a => a.AttributeType.FullName == "Java.Interop.DoNotPackageAttribute")) {
@@ -129,8 +133,11 @@ void AddAssemblyReferences (DirectoryAssemblyResolver resolver, ICollection<stri
 			Log.LogMessage (MessageImportance.Low, "{0}Adding assembly reference for {1}, recursively...", new string (' ', indent), assembly.Name);
 			indent += 2;
 			// Add this assembly
-			if (!topLevel && assemblies.All (a => new AssemblyNameDefinition (a, null).Name != assembly.Name.Name))
-				assemblies.Add (fullPath);
+			if (!topLevel && assemblies.All (a => new AssemblyNameDefinition (a.ItemSpec, null).Name != assembly.Name.Name)) {
+				var path = Path.GetDirectoryName (fullPath);
+				item.SetMetadata ("ResolvedFrom", DesignTimeFacadeDirectories.Any (x =>  Path.GetDirectoryName (x.ItemSpec).StartsWith (Path.GetDirectoryName (path))) ? "ImplicitlyExpandDesignTimeFacades" : "");
+				assemblies.Add (item);
+			}
 
 			// Recurse into each referenced assembly
 			foreach (AssemblyNameReference reference in assembly.MainModule.AssemblyReferences) {
@@ -152,7 +159,7 @@ static LinkModes ParseLinkMode (string linkmode)
 			return mode;
 		}
 
-		void AddI18nAssemblies (DirectoryAssemblyResolver resolver, ICollection<string> assemblies)
+		void AddI18nAssemblies (DirectoryAssemblyResolver resolver, ICollection<ITaskItem> assemblies)
 		{
 			var i18n = Linker.ParseI18nAssemblies (I18nAssemblies);
 			var link = ParseLinkMode (LinkMode);
@@ -179,10 +186,10 @@ void AddI18nAssemblies (DirectoryAssemblyResolver resolver, ICollection<string>
 				assemblies.Add (ResolveI18nAssembly (resolver, "I18N.West"));
 		}
 
-		string ResolveI18nAssembly (DirectoryAssemblyResolver resolver, string name)
+		ITaskItem ResolveI18nAssembly (DirectoryAssemblyResolver resolver, string name)
 		{
 			var assembly = resolver.Resolve (AssemblyNameReference.Parse (name));
-			return Path.GetFullPath (assembly.MainModule.FullyQualifiedName);
+			return new TaskItem (Path.GetFullPath (assembly.MainModule.FullyQualifiedName));
 		}
 	}
 }
diff --git a/src/Xamarin.Android.Build.Tasks/Utilities/ITaskItemEqualityComparer.cs b/src/Xamarin.Android.Build.Tasks/Utilities/ITaskItemEqualityComparer.cs
new file mode 100644
index 00000000000..2f081362666
--- /dev/null
+++ b/src/Xamarin.Android.Build.Tasks/Utilities/ITaskItemEqualityComparer.cs
@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using Microsoft.Build.Framework;
+
+namespace Xamarin.Android.Tasks
+{
+	public class ITaskItemEqualityComparer : IEqualityComparer<ITaskItem>
+	{
+		public bool Equals (ITaskItem x, ITaskItem y)
+		{
+			if (x == null || y == null)
+				return false;
+			return x.ItemSpec == y.ItemSpec;
+		}
+
+		public int GetHashCode (ITaskItem obj)
+		{
+			if (obj == null)
+				return 0;
+			return obj.ItemSpec.GetHashCode ();
+		}
+	}
+}
diff --git a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj
index 2324bb52335..93b775b0c06 100644
--- a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj
+++ b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj
@@ -393,6 +393,9 @@
     <Compile Include="Utilities\Files.cs">
       <Link>Utilities\Files.cs</Link>
     </Compile>
+    <Compile Include="Utilities\ITaskItemEqualityComparer.cs">
+      <Link>Utilities\ITaskItemEqualityComparer.cs</Link>
+    </Compile>
     <Compile Include="$(LinkerSourceFullPath)\tuner\Mono.Tuner\ApplyPreserveAttributeBase.cs">
       <Link>Linker\Mono.Tuner\ApplyPreserveAttributeBase.cs</Link>
     </Compile>
diff --git a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
index 2dbbb79d769..37c91084b6e 100755
--- a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
+++ b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
@@ -1234,6 +1234,7 @@ because xbuild doesn't support framework reference assemblies.
 		_GetAdditionalResourcesFromAssemblies;
 		_CreateAdditionalResourceCache;
 		_GenerateAndroidResourceDir;
+		_ValidateAndroidPackageProperties;
 	</_UpdateAndroidResgenDependsOnTargets>
 </PropertyGroup>
 
@@ -1407,6 +1408,7 @@ because xbuild doesn't support framework reference assemblies.
 		Assemblies="$(OutDir)$(TargetFileName);@(FilteredAssemblies)"
 		I18nAssemblies="$(MandroidI18n)"
 		LinkMode="$(AndroidLinkMode)"
+		DesignTimeFacadeDirectories="@(DesignTimeFacadeDirectories)"
 		ReferenceAssembliesDirectory="$(TargetFrameworkDirectory)">
       <Output TaskParameter="ResolvedAssemblies" ItemName="ResolvedAssemblies" />
       <Output TaskParameter="ResolvedUserAssemblies" ItemName="ResolvedUserAssemblies" />
@@ -1612,6 +1614,7 @@ because xbuild doesn't support framework reference assemblies.
 <Target Name="_PrepareAssemblies" DependsOnTargets="$(_PrepareAssembliesDependsOnTargets)">
   <!-- Update our assembly lists to the copies for linking.  We also need to verify
        they still exist cause linking will delete them if they aren't used -->
+
   <GetFilesThatExist
     Condition="'$(AndroidLinkMode)' != 'None'"
     Files="@(ResolvedAssemblies->'$(MonoAndroidIntermediateAssetsDir)%(Filename)%(Extension)')">
@@ -1638,36 +1641,42 @@ because xbuild doesn't support framework reference assemblies.
 
   <CreateItem
     Include="@(ResolvedAssemblies->'$(MonoAndroidIntermediateAssemblyDir)%(Filename)%(Extension)')"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' == 'None'">
     <Output TaskParameter="Include" ItemName="_ResolvedAssemblies" />
   </CreateItem>
 
   <CreateItem
     Include="@(ResolvedSymbols->'$(MonoAndroidIntermediateAssemblyDir)%(Filename)%(Extension)')"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' == 'None'">
     <Output TaskParameter="Include" ItemName="_ResolvedSymbols" />
   </CreateItem>
 
   <CreateItem
     Include="@(ResolvedUserAssemblies->'$(MonoAndroidIntermediateAssemblyDir)%(Filename)%(Extension)')"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' == 'None'">
     <Output TaskParameter="Include" ItemName="_ResolvedUserAssemblies" />
   </CreateItem>
 
   <CreateItem
     Include="@(ResolvedFrameworkAssemblies)"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' == 'None'">
     <Output TaskParameter="Include" ItemName="_ResolvedFrameworkAssemblies" />
   </CreateItem>
 
   <CreateItem
     Include="@(_ResolvedFrameworkAssemblies)"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' == 'None' OR '$(AndroidUseSharedRuntime)' == 'true'">
     <Output TaskParameter="Include" ItemName="_ShrunkFrameworkAssemblies" />
   </CreateItem>
 
   <CreateItem
     Include="@(_ResolvedFrameworkAssemblies->'$(MonoAndroidIntermediateAssetsDir)shrunk\%(Filename)%(Extension)')"
+    PreserveExistingMetadata="True"
     Condition="'$(AndroidLinkMode)' != 'None' AND '$(AndroidUseSharedRuntime)' != 'true'">
     <Output TaskParameter="Include" ItemName="_ShrunkFrameworkAssemblies" />
   </CreateItem>
@@ -1733,6 +1742,7 @@ because xbuild doesn't support framework reference assemblies.
 		_CheckDuplicateJavaLibraries;
 		_GetAdditionalResourcesFromAssemblies;
 		_CreateAdditionalResourceCache;
+		_DefineBuildTargetAbis;
 	</_CreateBaseApkDependsOnTargets>
 	<_CreateBaseApkInputs>
 		$(MSBuildAllProjects)
@@ -2149,6 +2159,12 @@ because xbuild doesn't support framework reference assemblies.
    <Touch Files="$(_AndroidApkPerAbiFlagFile)" Condition="'$(AndroidCreatePackagePerAbi)' == 'true'" AlwaysCreate="True" />
 </Target>
 
+<Target Name="FilterDesignTimeFacades">
+	<ItemGroup>
+		<_FilteredShrunkFrameworkAssemblies Include="@(_ShrunkFrameworkAssemblies)" Condition="'%(_ShrunkFrameworkAssemblies.ResolvedFrom)' != 'ImplicitlyExpandDesignTimeFacades'" />
+	</ItemGroup>
+</Target>
+
 <PropertyGroup>
 	<_PrepareBuildApkDependsOnTargets>
 		_SetLatestTargetFrameworkVersion;
@@ -2165,6 +2181,7 @@ because xbuild doesn't support framework reference assemblies.
 		_ResolveSatellitePaths;
 		_CheckApkPerAbiFlag
 		;_LintChecks
+		;FilterDesignTimeFacades
 	</_PrepareBuildApkDependsOnTargets>
 </PropertyGroup>
 
@@ -2200,7 +2217,7 @@ because xbuild doesn't support framework reference assemblies.
 	SupportedAbis="$(_BuildTargetAbis)"
 	AndroidSequencePointsMode="$(_SequencePointsMode)"
 	AotAdditionalArguments="$(AndroidAotAdditionalArguments)"
-	ResolvedAssemblies="@(_ResolvedUserAssemblies);@(_ShrunkFrameworkAssemblies)"
+	ResolvedAssemblies="@(_ResolvedUserAssemblies);@(_FilteredShrunkFrameworkAssemblies)"
 	AotOutputDirectory="$(_AndroidAotBinDirectory)"
 	IntermediateAssemblyDir="$(MonoAndroidIntermediateAssemblyDir)"
 	LinkMode="$(AndroidLinkMode)"
@@ -2214,14 +2231,14 @@ because xbuild doesn't support framework reference assemblies.
 	Condition=" '$(AndroidAotMode)' == 'Hybrid' And '$(AotAssemblies)' == 'True' "
 	AndroidAotMode="$(AndroidAotMode)"
 	ToolPath="$(_MonoAndroidToolsDirectory)"
-	ResolvedAssemblies="@(_ResolvedAssemblies)">
+	ResolvedAssemblies="@(_FilteredShrunkFrameworkAssemblies)">
   </CilStrip> 
 
   <!-- Bundle the assemblies into native libraries in the apk -->
   <MakeBundleNativeCodeExternal
 		Condition="'$(BundleAssemblies)' == 'True'"
 		AndroidNdkDirectory="$(_AndroidNdkDirectory)"
-		Assemblies="@(_ResolvedUserAssemblies);@(_AndroidResolvedSatellitePaths);@(_ShrunkFrameworkAssemblies)"
+		Assemblies="@(_ResolvedUserAssemblies);@(_AndroidResolvedSatellitePaths);@(_FilteredShrunkFrameworkAssemblies)"
 		IncludePath="$(MonoAndroidIncludeDirectory)"
 		SupportedAbis="$(_BuildTargetAbis)"
 		TempOutputPath="$(IntermediateOutputPath)"
@@ -2239,7 +2256,7 @@ because xbuild doesn't support framework reference assemblies.
     EmbedAssemblies="$(EmbedAssembliesIntoApk)"
     Environments="@(AndroidEnvironment);@(LibraryEnvironments)"
     ResolvedUserAssemblies="@(_ResolvedUserAssemblies);@(_AndroidResolvedSatellitePaths)"
-    ResolvedFrameworkAssemblies="@(_ShrunkFrameworkAssemblies)"
+    ResolvedFrameworkAssemblies="@(_FilteredShrunkFrameworkAssemblies)"
     NativeLibraries="@(AndroidNativeLibrary)"
     AdditionalNativeLibraryReferences="@(_AdditionalNativeLibraryReferences)"
     EmbeddedNativeLibraryAssemblies="$(OutDir)$(TargetFileName);@(ReferencePath);@(ReferenceDependencyPaths)"