diff --git a/Xamarin.Android.sln b/Xamarin.Android.sln
index 13b92eefa7f..cccead00b6a 100644
--- a/Xamarin.Android.sln
+++ b/Xamarin.Android.sln
@@ -41,6 +41,8 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Tools", "Tools", "{864062D3
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "jcw-gen", "external\Java.Interop\tools\jcw-gen\jcw-gen.csproj", "{52C7D9B6-E8C8-47D0-9471-652D278D7D77}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "jnimarshalmethod-gen", "external\Java.Interop\tools\jnimarshalmethod-gen\Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj", "{D1295A8F-4F42-461D-A046-564476C10002}"
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Java.Interop.Tools.JavaCallableWrappers", "external\Java.Interop\src\Java.Interop.Tools.JavaCallableWrappers\Java.Interop.Tools.JavaCallableWrappers.csproj", "{D18FCF91-8876-48A0-A693-2DC1E7D3D80A}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Xamarin.Android.Tools.ApiXmlAdjuster", "external\Java.Interop\src\Xamarin.Android.Tools.ApiXmlAdjuster\Xamarin.Android.Tools.ApiXmlAdjuster.csproj", "{1268EADF-8344-431C-81F6-FCB7CBC99F49}"
@@ -186,6 +188,10 @@ Global
 		{52C7D9B6-E8C8-47D0-9471-652D278D7D77}.Debug|AnyCPU.Build.0 = Debug|Any CPU
 		{52C7D9B6-E8C8-47D0-9471-652D278D7D77}.Release|AnyCPU.ActiveCfg = Release|Any CPU
 		{52C7D9B6-E8C8-47D0-9471-652D278D7D77}.Release|AnyCPU.Build.0 = Release|Any CPU
+		{D1295A8F-4F42-461D-A046-564476C10002}.Debug|AnyCPU.ActiveCfg = Debug|Any CPU
+		{D1295A8F-4F42-461D-A046-564476C10002}.Debug|AnyCPU.Build.0 = Debug|Any CPU
+		{D1295A8F-4F42-461D-A046-564476C10002}.Release|AnyCPU.ActiveCfg = Release|Any CPU
+		{D1295A8F-4F42-461D-A046-564476C10002}.Release|AnyCPU.Build.0 = Release|Any CPU
 		{D18FCF91-8876-48A0-A693-2DC1E7D3D80A}.Debug|AnyCPU.ActiveCfg = Debug|Any CPU
 		{D18FCF91-8876-48A0-A693-2DC1E7D3D80A}.Debug|AnyCPU.Build.0 = Debug|Any CPU
 		{D18FCF91-8876-48A0-A693-2DC1E7D3D80A}.Release|AnyCPU.ActiveCfg = Release|Any CPU
@@ -367,6 +373,7 @@ Global
 		{3F1F2F50-AF1A-4A5A-BEDB-193372F068D7} = {04E3E11E-B47D-4599-8AFC-50515A95E715}
 		{B17475BC-45A2-47A3-B8FC-62F3A0959EE0} = {04E3E11E-B47D-4599-8AFC-50515A95E715}
 		{52C7D9B6-E8C8-47D0-9471-652D278D7D77} = {864062D3-A415-4A6F-9324-5820237BA058}
+		{D1295A8F-4F42-461D-A046-564476C10002} = {864062D3-A415-4A6F-9324-5820237BA058}
 		{D18FCF91-8876-48A0-A693-2DC1E7D3D80A} = {864062D3-A415-4A6F-9324-5820237BA058}
 		{1268EADF-8344-431C-81F6-FCB7CBC99F49} = {864062D3-A415-4A6F-9324-5820237BA058}
 		{07BC4495-1267-4B78-9EA6-B76FEEA2A64A} = {864062D3-A415-4A6F-9324-5820237BA058}
diff --git a/build-tools/scripts/java-interop.dllmap b/build-tools/scripts/java-interop.dllmap
new file mode 100644
index 00000000000..989096481a4
--- /dev/null
+++ b/build-tools/scripts/java-interop.dllmap
@@ -0,0 +1,4 @@
+  <dllmap dll="java-interop" os="osx" target="lib/host-Darwin/libmono-android.debug.dylib" />
+  <dllmap dll="java-interop" os="linux" target="lib/host-Linux/libmono-android.debug.so" />
+  <dllmap dll="java-interop" os="windows" wordsize="64" target="lib/host-mxe-Win64/libmono-android.debug.dll" />
+  <dllmap dll="java-interop" os="windows" wordsize="32" target="lib/host-mxe-Win32/libmono-android.debug.dll" />
diff --git a/src/monodroid/monodroid.csproj b/src/monodroid/monodroid.csproj
index 8f5d5e2038b..8c7bdf0f2d3 100644
--- a/src/monodroid/monodroid.csproj
+++ b/src/monodroid/monodroid.csproj
@@ -32,6 +32,20 @@
       <Name>dependencies</Name>
       <ReferenceOutputAssembly>False</ReferenceOutputAssembly>
     </ProjectReference>
+    <!--
+      `jnimarshalmethod-gen.exe` needs to be built first because our
+      `_CreateJavaInteropDllConfigs` target replaces
+      `Java.Runtime.Environment.dll.config`, which will be created as
+      part of the `jnimarshalmethod-gen.exe` build.
+      
+      We don't want our updated version to be replaced by the
+      `jnimarshalmethod-gen.exe` build.
+      -->
+    <ProjectReference Include="..\..\external\Java.Interop\tools\jnimarshalmethod-gen\Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj">
+      <Project>{D1295A8F-4F42-461D-A046-564476C10002}</Project>
+      <Name>jnimarshalmethod-gen</Name>
+      <ReferenceOutputAssembly>False</ReferenceOutputAssembly>
+    </ProjectReference>
     <ProjectReference Include="..\..\src\mono-runtimes\mono-runtimes.csproj">
       <Project>{C03E6CF1-7460-4CDC-A4AB-292BBC0F61F2}</Project>
       <Name>mono-runtimes</Name>
diff --git a/src/monodroid/monodroid.targets b/src/monodroid/monodroid.targets
index 53b9ef0ac3d..6c7660505f5 100644
--- a/src/monodroid/monodroid.targets
+++ b/src/monodroid/monodroid.targets
@@ -5,6 +5,7 @@
   <Import Project="monodroid.projitems" />
   <Import Project="..\..\build-tools\scripts\RequiredPrograms.targets" />
   <UsingTask AssemblyFile="..\..\bin\Build$(Configuration)\Xamarin.Android.Tools.BootstrapTasks.dll" TaskName="Xamarin.Android.Tools.BootstrapTasks.GenerateMonoDroidIncludes" />
+  <UsingTask AssemblyFile="..\..\bin\Build$(Configuration)\xa-prep-tasks.dll" TaskName="Xamarin.Android.BuildTools.PrepTasks.ReplaceFileContents" />
   <PropertyGroup>
     <_Conf>$(Configuration.ToLowerInvariant())</_Conf>
   </PropertyGroup>
@@ -116,7 +117,7 @@
     </ItemGroup>
   </Target>
   <Target Name="_BuildHostRuntimes"
-      DependsOnTargets="_GetBuildHostRuntimes;_CreateJavaInteropDllConfig"
+      DependsOnTargets="_GetBuildHostRuntimes;_CreateJavaInteropDllConfigs"
       Inputs="@(_CFile);@(_UnixCFile)"
       Outputs="@(_HostRuntime->'$(OutputPath)%(OutputDirectory)\libmono-android.debug.%(NativeLibraryExtension)')">
     <Message Text="Building host runtime %(_HostRuntime.Identity) in $(OutputPath)%(_HostRuntime.OutputDirectory)"/>
@@ -143,20 +144,27 @@
         Command="%(_HostRuntime.Strip) %(_HostRuntime.StripFlags) &quot;$(OutputPath)%(_HostRuntime.OutputDirectory)\libmono-android.release.%(_HostRuntime.NativeLibraryExtension)&quot;"
     />
   </Target>
-  <Target Name="_CreateJavaInteropDllConfig"
-      Inputs="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Interop.dll"
-      Outputs="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Interop.dll.config">
+  <Target Name="_CreateJavaInteropDllConfigs"
+      Inputs="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Interop.dll;$(JavaInteropSourceDirectory)\src\Java.Runtime.Environment\Java.Runtime.Environment.dll.config"
+      Outputs="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Interop.dll.config;$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Runtime.Environment.dll.config">
+    <ReadLinesFromFile
+        File="../../build-tools/scripts/java-interop.dllmap">
+      <Output TaskParameter="Lines" ItemName="_JavaInteropDllMapContent" />
+    </ReadLinesFromFile>
     <WriteLinesToFile
         File="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Interop.dll.config"
-        Lines="&lt;configuration&gt;
-  &lt;dllmap dll=&quot;java-interop&quot; os=&quot;osx&quot; target=&quot;lib/host-Darwin/libmono-android.debug.dylib&quot; /&gt;
-  &lt;dllmap dll=&quot;java-interop&quot; os=&quot;linux&quot; target=&quot;lib/host-Linux/libmono-android.debug.so&quot; /&gt;
-  &lt;dllmap dll=&quot;java-interop&quot; os=&quot;windows&quot; wordsize=&quot;64&quot; target=&quot;lib/host-mxe-Win64/libmono-android.debug.dll&quot; /&gt;
-  &lt;dllmap dll=&quot;java-interop&quot; os=&quot;windows&quot; wordsize=&quot;32&quot; target=&quot;lib/host-mxe-Win32/libmono-android.debug.dll&quot; /&gt;
-&lt;/configuration&gt;"
+        Lines="&lt;configuration&gt;;@(_JavaInteropDllMapContent);&lt;/configuration&gt;"
         Overwrite="True"
-	/>
-    </Target>
+    />
+    <PropertyGroup>
+      <_DllMaps>@(_JavaInteropDllMapContent->'%(Identity)', '%0a  ')</_DllMaps>
+    </PropertyGroup>
+    <ReplaceFileContents
+        SourceFile="$(JavaInteropSourceDirectory)\src\Java.Runtime.Environment\Java.Runtime.Environment.dll.config"
+        DestinationFile="$(XAInstallPrefix)xbuild\Xamarin\Android\Java.Runtime.Environment.dll.config"
+        Replacements="&lt;configuration&gt;=&lt;configuration&gt;%0a  $(_DllMaps)"
+    />
+  </Target>
   <Target Name="CoreCompile"
       DependsOnTargets="Build">
   </Target>