diff --git a/build-tools/android-toolchain/android-toolchain.projitems b/build-tools/android-toolchain/android-toolchain.projitems
index 7ddf02309b3..ce7ad78a844 100644
--- a/build-tools/android-toolchain/android-toolchain.projitems
+++ b/build-tools/android-toolchain/android-toolchain.projitems
@@ -137,7 +137,7 @@
   </ItemGroup>
   <ItemGroup>
     <_NdkToolchain Include="arm-linux-androideabi-clang" Condition="$(AndroidSupportedTargetJitAbisForConditionalChecks.Contains(':armeabi:')) Or $(AndroidSupportedTargetJitAbisForConditionalChecks.Contains(':armeabi-v7a:')) Or $(AndroidSupportedTargetAotAbisForConditionalChecks.Contains (':win-armeabi:'))">
-      <Platform>9</Platform>
+      <Platform>14</Platform>
       <Arch>arm</Arch>
     </_NdkToolchain>
     <_NdkToolchain Include="aarch64-linux-android-clang" Condition="$(AndroidSupportedTargetJitAbisForConditionalChecks.Contains(':arm64-v8a:')) Or $(AndroidSupportedTargetAotAbisForConditionalChecks.Contains (':win-arm64:'))">
@@ -145,7 +145,7 @@
       <Arch>arm64</Arch>
     </_NdkToolchain>
     <_NdkToolchain Include="x86-clang" Condition="$(AndroidSupportedTargetJitAbisForConditionalChecks.Contains(':x86:')) Or $(AndroidSupportedTargetAotAbisForConditionalChecks.Contains (':win-x86:'))">
-      <Platform>9</Platform>
+      <Platform>14</Platform>
       <Arch>x86</Arch>
     </_NdkToolchain>
     <_NdkToolchain Include="x86_64-clang" Condition="$(AndroidSupportedTargetJitAbisForConditionalChecks.Contains(':x86_64:')) Or $(AndroidSupportedTargetAotAbisForConditionalChecks.Contains (':win-x86_64:'))">
diff --git a/build-tools/scripts/RunTests.targets b/build-tools/scripts/RunTests.targets
index 92ce345062c..78708ec8fde 100644
--- a/build-tools/scripts/RunTests.targets
+++ b/build-tools/scripts/RunTests.targets
@@ -17,6 +17,7 @@
     <_TestAssembly Include="$(_TopDir)\bin\Test$(Configuration)\Xamarin.Android.Build.Tests.dll" />
     <_ApkTestProject Include="$(_TopDir)\src\Mono.Android\Test\Mono.Android-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\CodeGen-Binding\Xamarin.Android.JcwGen-Tests\Xamarin.Android.JcwGen-Tests.csproj" />
+    <_ApkTestProject Include="$(_TopDir)\tests\CodeGen-MkBundle\Xamarin.Android.MakeBundle-Tests\Xamarin.Android.MakeBundle-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\locales\Xamarin.Android.Locale-Tests\Xamarin.Android.Locale-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\Xamarin.Android.Bcl-Tests\Xamarin.Android.Bcl-Tests.csproj" />
     <_ApkTestProject Include="$(_TopDir)\tests\Xamarin.Forms-Performance-Integration\Droid\Xamarin.Forms.Performance.Integration.Droid.csproj" />
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/MakeBundleNativeCodeExternal.cs b/src/Xamarin.Android.Build.Tasks/Tasks/MakeBundleNativeCodeExternal.cs
index 9399ca438b4..9405388bfe5 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/MakeBundleNativeCodeExternal.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/MakeBundleNativeCodeExternal.cs
@@ -169,12 +169,24 @@ bool DoExecute ()
 
 				clb = new CommandLineBuilder ();
 				clb.AppendSwitch ("-c");
+
+				// This is necessary only when unified headers are in use but it won't hurt to have it
+				// defined even if we don't use them
+				clb.AppendSwitch ($"-D__ANDROID_API__={level}");
+
 				clb.AppendSwitch ("-o");
 				clb.AppendFileNameIfNotNull (Path.Combine (outpath, "temp.o"));
 				if (!string.IsNullOrWhiteSpace (IncludePath)) {
 					clb.AppendSwitch ("-I");
 					clb.AppendFileNameIfNotNull (IncludePath);
 				}
+
+				string asmIncludePath = NdkUtil.GetNdkAsmIncludePath (AndroidNdkDirectory, arch, level);
+				if (!String.IsNullOrEmpty (asmIncludePath)) {
+					clb.AppendSwitch ("-I");
+					clb.AppendFileNameIfNotNull (asmIncludePath);
+				}
+
 				clb.AppendSwitch ("-I");
 				clb.AppendFileNameIfNotNull (NdkUtil.GetNdkPlatformIncludePath (AndroidNdkDirectory, arch, level));
 				clb.AppendFileNameIfNotNull (Path.Combine (outpath, "temp.c"));
diff --git a/src/Xamarin.Android.Build.Tasks/Tasks/NdkUtils.cs b/src/Xamarin.Android.Build.Tasks/Tasks/NdkUtils.cs
index ce89695662a..5ffc0820866 100644
--- a/src/Xamarin.Android.Build.Tasks/Tasks/NdkUtils.cs
+++ b/src/Xamarin.Android.Build.Tasks/Tasks/NdkUtils.cs
@@ -95,11 +95,69 @@ public static string GetNdkTool (string androidNdkPath, AndroidTargetArch arch,
 			return null;
 		}
 
-		public static string GetNdkPlatformIncludePath (string androidNdkPath, AndroidTargetArch arch, int level)
+		static string GetUnifiedHeadersPath (string androidNdkPath)
+		{
+			return Path.Combine (androidNdkPath, "sysroot", "usr", "include");
+		}
+
+		static string GetPerPlatformHeadersPath (string androidNdkPath, AndroidTargetArch arch, int level)
+		{
+			return Path.Combine (androidNdkPath, "platforms", "android-" + level, "arch-" + GetPlatformArch (arch), "usr", "include");
+		}
+
+		public static string GetNdkAsmIncludePath (string androidNdkPath, AndroidTargetArch arch, int level)
 		{
-			string path = Path.Combine (androidNdkPath, "platforms", "android-" + level, "arch-" + GetPlatformArch (arch), "usr", "include");
+			string path = GetPerPlatformHeadersPath (androidNdkPath, arch, level);
+			if (Directory.Exists (path))
+				return null;
+
+			path = GetUnifiedHeadersPath (androidNdkPath);
 			if (!Directory.Exists (path))
+				return null;
+
+			string archDir = null;
+			switch (arch) {
+				case AndroidTargetArch.Arm:
+					archDir = "arm-linux-androideabi";
+					break;
+
+				case AndroidTargetArch.Arm64:
+					archDir = "aarch64-linux-android";
+					break;
+
+				case AndroidTargetArch.Mips:
+					archDir = "mipsel-linux-android";
+					break;
+
+				case AndroidTargetArch.X86:
+					archDir = "i686-linux-android";
+					break;
+
+				case AndroidTargetArch.X86_64:
+					archDir = "x86_64-linux-android";
+					break;
+			}
+
+			if (archDir == null)
+				return null;
+
+			return Path.Combine (path, archDir);
+		}
+
+		public static string GetNdkPlatformIncludePath (string androidNdkPath, AndroidTargetArch arch, int level)
+		{
+			// This is for NDK older than r16 which isn't configured to use unified headers. We
+			string path = GetPerPlatformHeadersPath (androidNdkPath, arch, level);
+			if (!Directory.Exists (path)) {
+				// This is for NDK r15 (if configured to use unified headers) or NDK r16+ (which doesn't have
+				// the per-platform includes anymore)
+				path = GetUnifiedHeadersPath (androidNdkPath);
+				if (Directory.Exists (path))
+					return path;
+
 				throw new InvalidOperationException (String.Format ("Platform header files for target {0} and API Level {1} was not found. Expected path is \"{2}\"", arch, level, path));
+			}
+
 			return path;
 		}
 
@@ -257,7 +315,7 @@ public static IEnumerable<int> GetSupportedPlatforms (string androidNdkPath)
 
 		public static int GetMinimumApiLevelFor (AndroidTargetArch arch, string androidNdkPath)
 		{
-			var minValue = NdkUtil.IsNdk64BitArch (arch) ? 21 : arch == AndroidTargetArch.Arm ? 4 : 9;
+			var minValue = NdkUtil.IsNdk64BitArch (arch) ? 21 : 14;
 			var platforms = GetSupportedPlatforms (androidNdkPath).OrderBy (x => x).Where (x => x >= minValue);
 			return platforms.First (x => Directory.Exists (Path.Combine (androidNdkPath, "platforms", $"android-{x}", $"arch-{archPathMap[arch]}")));
 		}