diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/GeneratePackageManagerJava.cs b/src/Xamarin.Android.Build.Tasks/Tasks/GeneratePackageManagerJava.cs
index 9017c98bea9..7935fb757d3 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/GeneratePackageManagerJava.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/GeneratePackageManagerJava.cs
@@ -188,7 +188,7 @@ void AddEnvironment ()
 			}
 
 			if (!havebuildId)
-				WriteEnvironment ("XAMARIN_BUILD_ID", buildId.ToString ());
+				WriteEnvironment ("XAMARIN_BUILD_ID", BuildId);
 
 			if (!haveHttpMessageHandler) {
 				if (HttpClientHandlerType == null)
diff --git a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
index 84e170126b0..108dad49190 100755
--- a/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
+++ b/src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets
@@ -273,6 +273,8 @@ Copyright (C) 2011-2012 Xamarin. All rights reserved.
 	<_AndroidIntermediateDesignTimeBuildDirectory>$(IntermediateOutputPath)designtime\</_AndroidIntermediateDesignTimeBuildDirectory>
 	<_AndroidLibraryFlatArchivesDirectory>$(IntermediateOutputPath)flata\</_AndroidLibraryFlatArchivesDirectory>
 	<_AndroidStampDirectory>$(IntermediateOutputPath)stamp\</_AndroidStampDirectory>
+	<_AndroidBuildIdFile>$(IntermediateOutputPath)buildid.txt</_AndroidBuildIdFile>
+	<_ResolvedUserAssembliesHashFile>$(IntermediateOutputPath)resolvedassemblies.hash</_ResolvedUserAssembliesHashFile>
 
 	<!-- $(EnableProguard) is an obsolete property that should be removed at some stage. -->
 	<AndroidEnableProguard Condition=" '$(AndroidEnableProguard)' == '' ">$(EnableProguard)</AndroidEnableProguard>
@@ -1940,6 +1942,18 @@ because xbuild doesn't support framework reference assemblies.
       <Output TaskParameter="ResolvedSymbols" ItemName="ResolvedSymbols" />
       <Output TaskParameter="ResolvedDoNotPackageAttributes" ItemName="_ResolvedDoNotPackageAttributes" />
   </ResolveAssemblies>
+  <Hash ItemsToHash="@(ResolvedAssemblies)">
+    <Output TaskParameter="HashResult" PropertyName="_ResolvedUserAssembliesHash" />
+  </Hash>
+  <WriteLinesToFile
+      File="$(_ResolvedUserAssembliesHashFile)"
+      Lines="$(_ResolvedUserAssembliesHash)"
+      Overwrite="true"
+      WriteOnlyWhenDifferent="true"
+  />
+  <ItemGroup>
+    <FileWrites Include="$(_ResolvedUserAssembliesHashFile)" />
+  </ItemGroup>
 </Target>
 
 <Target Name="_CreatePackageWorkspace">
@@ -2368,7 +2382,7 @@ because xbuild doesn't support framework reference assemblies.
 
 <Target Name="_GeneratePackageManagerJava"
   DependsOnTargets="_GetAddOnPlatformLibraries;_AddStaticResources;$(_AfterAddStaticResources);_PrepareAssemblies"
-  Inputs="$(MSBuildAllProjects);@(_ResolvedAssemblies);@(_ResolvedUserAssemblies);$(MSBuildProjectFile);$(_AndroidBuildPropertiesCache)"
+  Inputs="$(MSBuildAllProjects);$(_ResolvedUserAssembliesHashFile);$(MSBuildProjectFile);$(_AndroidBuildPropertiesCache)"
   Outputs="$(_AndroidStampDirectory)_GeneratePackageManagerJava.stamp">
   <!-- Create java needed for Mono runtime -->
   <GeneratePackageManagerJava
@@ -2387,10 +2401,20 @@ because xbuild doesn't support framework reference assemblies.
     TlsProvider="$(AndroidTlsProvider)"
     Debug="$(AndroidIncludeDebugSymbols)"
     AndroidSequencePointsMode="$(_SequencePointsMode)"
-    EnableSGenConcurrent="$(AndroidEnableSGenConcurrent)">
+    EnableSGenConcurrent="$(AndroidEnableSGenConcurrent)"
+  >
     <Output TaskParameter="BuildId" PropertyName="_XamarinBuildId" />
   </GeneratePackageManagerJava>
   <Touch Files="$(_AndroidStampDirectory)_GeneratePackageManagerJava.stamp" AlwaysCreate="True" />
+  <WriteLinesToFile
+      File="$(_AndroidBuildIdFile)"
+      Lines="$(_XamarinBuildId)"
+      Overwrite="true"
+      WriteOnlyWhenDifferent="true"
+  />
+  <ItemGroup>
+    <FileWrites Include="$(_AndroidBuildIdFile)" />
+  </ItemGroup>
 </Target>
 
 <PropertyGroup>
@@ -2986,6 +3010,10 @@ because xbuild doesn't support framework reference assemblies.
     DestinationFolder="$(OutDir)$(_AndroidPackage).apk.mSYM\%(_SymbolicateFiles.RecursiveDir)"
     SkipUnchangedFiles="true"
   />
+		
+  <ReadLinesFromFile File="$(_AndroidBuildIdFile)" Condition="Exists('$(_AndroidBuildIdFile)') And '$(_XamarinBuildId)' == ''">
+    <Output TaskParameter="Lines" PropertyName="_XamarinBuildId"/>
+  </ReadLinesFromFile>
 
   <CreateMsymManifest
      Condition=" '$(_XamarinBuildId)' != '' And '$(MonoSymbolArchive)' == 'True' "
@@ -3246,6 +3274,8 @@ because xbuild doesn't support framework reference assemblies.
 	<Delete Files="$(_AndroidAapt2VersionFile)" />
 	<Delete Files="$(IntermediateOutputPath)R.txt" />
 	<Delete Files="$(_AndroidMainDexListFile)" />
+	<Delete Files="$(_AndroidBuildIdFile)" />
+	<Delete Files="$(_ResolvedUserAssembliesHashFile)" />
 </Target>
 
 <Target Name="_CollectMonoAndroidOutputs" DependsOnTargets="_ValidateAndroidPackageProperties">