diff --git a/.gitmodules b/.gitmodules
index e7be856691f..49b161473b8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -5,7 +5,7 @@
 [submodule "external/mono"]
 	path = external/mono
 	url = https://github.com/mono/mono.git
-	branch = 2017-02
+	branch = 2017-04
 [submodule "external/mxe"]
 	path = external/mxe
 	url = https://github.com/xamarin/mxe.git
diff --git a/Configuration.props b/Configuration.props
index 55625b3689c..be73e15b183 100644
--- a/Configuration.props
+++ b/Configuration.props
@@ -51,7 +51,7 @@
     <JavaInteropSourceDirectory Condition=" '$(JavaInteropSourceDirectory)' == '' ">$(MSBuildThisFileDirectory)external\Java.Interop</JavaInteropSourceDirectory>
     <LlvmSourceDirectory Condition=" '$(LlvmSourceDirectory)' == '' ">$(MSBuildThisFileDirectory)external\llvm</LlvmSourceDirectory>
     <MonoSourceDirectory>$(MSBuildThisFileDirectory)external\mono</MonoSourceDirectory>
-    <MonoRequiredMinimumVersion Condition=" '$(MonoRequiredMinimumVersion)' == '' ">4.9.3</MonoRequiredMinimumVersion>
+    <MonoRequiredMinimumVersion Condition=" '$(MonoRequiredMinimumVersion)' == '' ">5.2.0</MonoRequiredMinimumVersion>
     <LinkerSourceDirectory>$(MSBuildThisFileDirectory)external\linker</LinkerSourceDirectory>
     <OpenTKSourceDirectory>$(MSBuildThisFileDirectory)external\opentk</OpenTKSourceDirectory>
     <LibZipSourceDirectory Condition=" '$(LibZipSourceDirectory)' == '' ">$(MSBuildThisFileDirectory)external\libzip</LibZipSourceDirectory>
diff --git a/build-tools/dependencies/dependencies.projitems b/build-tools/dependencies/dependencies.projitems
index 54f2ffc4c33..87198aa8a3f 100644
--- a/build-tools/dependencies/dependencies.projitems
+++ b/build-tools/dependencies/dependencies.projitems
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
-    <_DarwinMonoFramework>MonoFramework-MDK-4.9.3.6.macos10.xamarin.universal.pkg</_DarwinMonoFramework>
+    <_DarwinMonoFramework>MonoFramework-MDK-5.2.0.20.macos10.xamarin.universal.pkg</_DarwinMonoFramework>
     <_AptGetInstall>apt-get -f -u install</_AptGetInstall>
   </PropertyGroup>
   <ItemGroup>
@@ -59,7 +59,7 @@
     <RequiredProgram Include="$(ManagedRuntime)"    Condition=" '$(ManagedRuntime)' != '' ">
       <MinimumVersion>$(MonoRequiredMinimumVersion)</MinimumVersion>
       <CurrentVersionCommand>$(MSBuildThisFileDirectory)..\scripts\mono-version</CurrentVersionCommand>
-      <DarwinMinimumUrl>https://bosstoragemirror.blob.core.windows.net/wrench/mono-2017-02/c5/c52c4bd713e19339a5859e73a99dbb4cc21c6d3f/$(_DarwinMonoFramework)</DarwinMinimumUrl>
+      <DarwinMinimumUrl>https://bosstoragemirror.blob.core.windows.net/wrench/mono-2017-04/92/92503db79568d1ef66a5445cb889ccbb8c8bd343/$(_DarwinMonoFramework)</DarwinMinimumUrl>
       <DarwinInstall>installer -pkg "$(AndroidToolchainCacheDirectory)\$(_DarwinMonoFramework)" -target /</DarwinInstall>
     </RequiredProgram>
   </ItemGroup>
diff --git a/build-tools/mono-runtimes/ProfileAssemblies.projitems b/build-tools/mono-runtimes/ProfileAssemblies.projitems
index db880b73b71..63b9a734804 100644
--- a/build-tools/mono-runtimes/ProfileAssemblies.projitems
+++ b/build-tools/mono-runtimes/ProfileAssemblies.projitems
@@ -64,6 +64,7 @@
     <MonoFacadeAssembly Include="System.Net.WebSockets.dll" />
     <MonoFacadeAssembly Include="System.ObjectModel.dll" />
     <MonoFacadeAssembly Include="System.Reflection.dll" />
+    <MonoFacadeAssembly Include="System.Reflection.DispatchProxy.dll" />
     <MonoFacadeAssembly Include="System.Reflection.Emit.dll" />
     <MonoFacadeAssembly Include="System.Reflection.Emit.ILGeneration.dll" />
     <MonoFacadeAssembly Include="System.Reflection.Emit.Lightweight.dll" />
@@ -77,7 +78,9 @@
     <MonoFacadeAssembly Include="System.Runtime.Extensions.dll" />
     <MonoFacadeAssembly Include="System.Runtime.Handles.dll" />
     <MonoFacadeAssembly Include="System.Runtime.InteropServices.dll" />
+    <MonoFacadeAssembly Include="System.Runtime.InteropServices.RuntimeInformation.dll" />
     <MonoFacadeAssembly Include="System.Runtime.InteropServices.WindowsRuntime.dll" />
+    <MonoFacadeAssembly Include="System.Runtime.Loader.dll" />
     <MonoFacadeAssembly Include="System.Runtime.Numerics.dll" />
     <MonoFacadeAssembly Include="System.Runtime.Serialization.Formatters.dll" />
     <MonoFacadeAssembly Include="System.Runtime.Serialization.Json.dll" />
@@ -131,6 +134,7 @@
     <MonoFacadeAssembly Include="System.Xml.XmlSerializer.dll" />
     <MonoFacadeAssembly Include="System.Xml.XPath.dll" />
     <MonoFacadeAssembly Include="System.Xml.XPath.XDocument.dll" />
+    <MonoFacadeAssembly Include="System.Xml.XPath.XmlDocument.dll" />
     <MonoFacadeAssembly Include="System.Xml.Xsl.Primitives.dll" />
     <!--
       System.Drawing.Primitives and netstandard need a reference to Mono.Android.dll so their
@@ -172,8 +176,6 @@
     <MonoProfileAssembly Include="System.Numerics.dll" />
     <MonoProfileAssembly Include="System.Numerics.Vectors.dll" />
     <MonoProfileAssembly Include="System.Reflection.Context.dll" />
-    <MonoProfileAssembly Include="System.Reflection.DispatchProxy.dll" />
-    <MonoProfileAssembly Include="System.Runtime.InteropServices.RuntimeInformation.dll" />
     <MonoProfileAssembly Include="System.Runtime.Serialization.dll" />
     <MonoProfileAssembly Include="System.Security.dll" />
     <MonoProfileAssembly Include="System.ServiceModel.dll" />
@@ -185,6 +187,5 @@
     <MonoProfileAssembly Include="System.Xml.dll" />
     <MonoProfileAssembly Include="System.Xml.Linq.dll" />
     <MonoProfileAssembly Include="System.Xml.Serialization.dll" />
-    <MonoProfileAssembly Include="System.Xml.XPath.XmlDocument.dll" />
   </ItemGroup>
 </Project>
diff --git a/build-tools/scripts/UnitTestApks.targets b/build-tools/scripts/UnitTestApks.targets
index fac835866a0..9ad5d1f90cc 100644
--- a/build-tools/scripts/UnitTestApks.targets
+++ b/build-tools/scripts/UnitTestApks.targets
@@ -8,7 +8,7 @@
 
   <PropertyGroup>
     <_TestImageName>XamarinAndroidUnitTestRunner</_TestImageName>
-    <_AdbEmulatorPort>5600</_AdbEmulatorPort>
+    <_AdbEmulatorPort>5570</_AdbEmulatorPort>
   </PropertyGroup>
 
   <Target Name="AcquireAndroidTarget">
diff --git a/external/linker b/external/linker
index 81007dfb0c4..c7450ca2669 160000
--- a/external/linker
+++ b/external/linker
@@ -1 +1 @@
-Subproject commit 81007dfb0c48c1908d7540571d76fc7107128714
+Subproject commit c7450ca2669becddffdea7dcdcc06692e57989e1
diff --git a/external/mono b/external/mono
index 1298269b884..24c4d616ab0 160000
--- a/external/mono
+++ b/external/mono
@@ -1 +1 @@
-Subproject commit 1298269b88479747947d332c8ae7c0e8222a3b8c
+Subproject commit 24c4d616ab0f65f75e7cae59478be84a6088124c
diff --git a/src/Mono.Posix/Mono.Posix.csproj b/src/Mono.Posix/Mono.Posix.csproj
index 14f1a3f53fb..09c4407b2ec 100644
--- a/src/Mono.Posix/Mono.Posix.csproj
+++ b/src/Mono.Posix/Mono.Posix.csproj
@@ -68,9 +68,6 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="$(XamarinAndroidSourcePath)\src\Mono.Posix\Mono.Unix.Native\NativeConvert.Android.cs" />
-    <Compile Include="$(XamarinAndroidSourcePath)\src\Mono.Posix\Mono.Unix.Android\AndroidUtils.cs" />
-
     <Compile Include="$(XamarinAndroidSourcePath)\src\Mono.Android\Android.Runtime\CPUArchitecture.cs">
       <Link>Android.Runtime\CPUArchitecture.cs</Link>
     </Compile>
@@ -128,6 +125,9 @@
     <Compile Include="$(MonoSourceDirectory)\mcs\class\Mono.Posix\Mono.Unix.Native\NativeConvert.cs">
       <Link>Mono.Unix.Native\NativeConvert.cs</Link>
     </Compile>
+    <Compile Include="$(MonoSourceDirectory)\mcs\class\Mono.Posix\Mono.Unix.Android\AndroidUtils.cs">
+      <Link>Mono.Unix.Android\AndroidUtils.cs</Link>
+    </Compile>
     <Compile Include="$(MonoSourceDirectory)\mcs\class\Mono.Posix\Mono.Unix.Native\NativeConvert.generated.cs">
       <Link>Mono.Unix.Native\NativeConvert.generated.cs</Link>
     </Compile>
diff --git a/src/System.Drawing.Primitives/System.Drawing.Primitives.targets b/src/System.Drawing.Primitives/System.Drawing.Primitives.targets
index 00b4e787e97..b9edb3fecdd 100644
--- a/src/System.Drawing.Primitives/System.Drawing.Primitives.targets
+++ b/src/System.Drawing.Primitives/System.Drawing.Primitives.targets
@@ -7,7 +7,7 @@
         Properties="Configuration=$(Configuration)">
       <Output TaskParameter="TargetOutputs" ItemName="MonoAndroidAssembly" />
     </MSBuild>
-    <Exec Command="make -C $(MonoSourceFullPath)\mcs\class\Facades\System.Drawing.Primitives PROFILE=monodroid EXTRA_LIB_MCS_FLAGS=&quot;-r:%(MonoAndroidAssembly.Identity)&quot;" />
+    <Exec Command="make -C $(MonoSourceFullPath)\mcs\class\Facades\System.Drawing.Primitives PROFILE=monodroid EXTERNAL_FACADE_DRAWING_REFERENCE=&quot;%(MonoAndroidAssembly.Identity)&quot;" />
     <Copy
         SourceFiles="$(MonoSourceFullPath)\mcs\class\lib\monodroid\Facades\System.Drawing.Primitives.dll"
         DestinationFiles="$(OutputPath)\System.Drawing.Primitives.dll"
diff --git a/src/Xamarin.Android.Build.Tasks/Linker/Mobile.Tuner/MobileProfile.cs b/src/Xamarin.Android.Build.Tasks/Linker/Mobile.Tuner/MobileProfile.cs
index 1df80e5543c..c85027cc5f0 100644
--- a/src/Xamarin.Android.Build.Tasks/Linker/Mobile.Tuner/MobileProfile.cs
+++ b/src/Xamarin.Android.Build.Tasks/Linker/Mobile.Tuner/MobileProfile.cs
@@ -29,9 +29,7 @@ public abstract class MobileProfile : Profile {
 			"System.Numerics",
 			"System.Numerics.Vectors",
 			"System.Reflection.Context",
-			"System.Reflection.DispatchProxy",
 			"System.Runtime.Serialization",
-			"System.Runtime.InteropServices.RuntimeInformation",
 			"System.Security",
 			"System.ServiceModel",
 			"System.ServiceModel.Internals",
@@ -42,7 +40,6 @@ public abstract class MobileProfile : Profile {
 			"System.Xml",
 			"System.Xml.Linq",
 			"System.Xml.Serialization",
-			"System.Xml.XPath.XmlDocument",
 			"Microsoft.CSharp",
 			"Microsoft.VisualBasic",
 			"Mono.CSharp",
@@ -118,6 +115,7 @@ public abstract class MobileProfile : Profile {
 			"System.Net.WebSockets.Client",
 			"System.Net.WebSockets",
 			"System.ObjectModel",
+			"System.Reflection.DispatchProxy",
 			"System.Reflection.Emit.ILGeneration",
 			"System.Reflection.Emit.Lightweight",
 			"System.Reflection.Emit",
@@ -131,7 +129,9 @@ public abstract class MobileProfile : Profile {
 			"System.Runtime.Extensions",
 			"System.Runtime.Handles",
 			"System.Runtime.InteropServices",
+			"System.Runtime.InteropServices.RuntimeInformation",
 			"System.Runtime.InteropServices.WindowsRuntime",
+			"System.Runtime.Loader",
 			"System.Runtime.Numerics",
 			"System.Runtime.Serialization.Formatters",
 			"System.Runtime.Serialization.Json",
@@ -183,6 +183,7 @@ public abstract class MobileProfile : Profile {
 			"System.Xml.ReaderWriter",
 			"System.Xml.XDocument",
 			"System.Xml.XPath.XDocument",
+			"System.Xml.XPath.XmlDocument",
 			"System.Xml.XPath",
 			"System.Xml.XmlDocument",
 			"System.Xml.XmlSerializer",
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 b452d1416db..e2586cafde4 100644
--- a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj
+++ b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Build.Tasks.csproj
@@ -343,6 +343,12 @@
     <Compile Include="$(LinkerSourceFullPath)\linker\Mono.Linker.Steps\MarkStep.cs">
       <Link>Linker\Mono.Linker.Steps\MarkStep.cs</Link>
     </Compile>
+    <Compile Include="$(LinkerSourceFullPath)\linker\Mono.Linker\LoadException.cs">
+      <Link>Linker\Mono.Linker\LoadException.cs</Link>
+    </Compile>
+    <Compile Include="$(LinkerSourceFullPath)\linker\Mono.Linker\MarkException.cs">
+      <Link>Linker\Mono.Linker\MarkException.cs</Link>
+    </Compile>
     <Compile Include="Tasks\MergeResources.cs" />
     <Compile Include="Tasks\GetConvertedJavaLibraries.cs" />
     <Compile Include="Tasks\JavaCompileToolTask.cs" />
diff --git a/src/netstandard/netstandard.targets b/src/netstandard/netstandard.targets
index 8349a475724..2c468100eca 100644
--- a/src/netstandard/netstandard.targets
+++ b/src/netstandard/netstandard.targets
@@ -7,7 +7,7 @@
         Properties="Configuration=$(Configuration)">
       <Output TaskParameter="TargetOutputs" ItemName="MonoAndroidAssembly" />
     </MSBuild>
-    <Exec Command="make -C $(MonoSourceFullPath)\mcs\class\Facades\netstandard PROFILE=monodroid EXTRA_LIB_MCS_FLAGS=&quot;-r:%(MonoAndroidAssembly.Identity)&quot;" />
+    <Exec Command="make -C $(MonoSourceFullPath)\mcs\class\Facades\netstandard PROFILE=monodroid EXTERNAL_FACADE_DRAWING_REFERENCE=&quot;%(MonoAndroidAssembly.Identity)&quot;" />
     <Copy
         SourceFiles="$(MonoSourceFullPath)\mcs\class\lib\monodroid\Facades\netstandard.dll"
         DestinationFiles="$(OutputPath)\netstandard.dll"