diff --git a/java/builder.go b/java/builder.go
index f1a6ead..40f72e1 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -200,7 +200,7 @@
 		// ensure java does not fall back to the default bootclasspath.
 		bootClasspath = `--bootclasspath ""`
 	} else {
-		bootClasspath = strings.Join(flags.bootClasspath.FormTurbineClasspath("--bootclasspath"), " ")
+		bootClasspath = strings.Join(flags.bootClasspath.FormTurbineClasspath("--bootclasspath "), " ")
 	}
 
 	ctx.Build(pctx, android.BuildParams{
@@ -213,7 +213,7 @@
 			"javacFlags":    flags.javacFlags,
 			"bootClasspath": bootClasspath,
 			"srcJars":       strings.Join(srcJars.Strings(), " "),
-			"classpath":     strings.Join(flags.classpath.FormTurbineClasspath("--classpath"), " "),
+			"classpath":     strings.Join(flags.classpath.FormTurbineClasspath("--classpath "), " "),
 			"outDir":        android.PathForModuleOut(ctx, "turbine", "classes").String(),
 			"javaVersion":   flags.javaVersion,
 		},
@@ -415,7 +415,7 @@
 	}
 	flags := make([]string, len(*x))
 	for i, v := range *x {
-		flags[i] = optName + " " + v.String()
+		flags[i] = optName + v.String()
 	}
 
 	return flags
diff --git a/java/config/kotlin.go b/java/config/kotlin.go
index 432840e..2af7b3c 100644
--- a/java/config/kotlin.go
+++ b/java/config/kotlin.go
@@ -14,6 +14,8 @@
 
 package config
 
+import "strings"
+
 var (
 	KotlinStdlibJar     = "external/kotlinc/lib/kotlin-stdlib.jar"
 	KotlincIllegalFlags = []string{
@@ -25,5 +27,14 @@
 func init() {
 	pctx.SourcePathVariable("KotlincCmd", "external/kotlinc/bin/kotlinc")
 	pctx.SourcePathVariable("KotlinCompilerJar", "external/kotlinc/lib/kotlin-compiler.jar")
+	pctx.SourcePathVariable("KotlinKaptJar", "external/kotlinc/lib/kotlin-annotation-processing.jar")
 	pctx.SourcePathVariable("KotlinStdlibJar", KotlinStdlibJar)
+
+	// These flags silence "Illegal reflective access" warnings when running kotlinc in OpenJDK9
+	pctx.StaticVariable("KotlincSuppressJDK9Warnings", strings.Join([]string{
+		"-J--add-exports=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED",
+		"-J--add-exports=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED",
+		"-J--add-exports=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED",
+		"-J--add-opens=java.base/sun.net.www.protocol.jar=ALL-UNNAMED",
+	}, " "))
 }
diff --git a/java/dex.go b/java/dex.go
index a6d486a..2531970 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -85,8 +85,8 @@
 func (j *Module) d8Flags(ctx android.ModuleContext, flags javaBuilderFlags) ([]string, android.Paths) {
 	d8Flags := j.dexCommonFlags(ctx)
 
-	d8Flags = append(d8Flags, flags.bootClasspath.FormTurbineClasspath("--lib")...)
-	d8Flags = append(d8Flags, flags.classpath.FormTurbineClasspath("--lib")...)
+	d8Flags = append(d8Flags, flags.bootClasspath.FormTurbineClasspath("--lib ")...)
+	d8Flags = append(d8Flags, flags.classpath.FormTurbineClasspath("--lib ")...)
 
 	var d8Deps android.Paths
 	d8Deps = append(d8Deps, flags.bootClasspath...)
diff --git a/java/java.go b/java/java.go
index d2710a8..f3b47be 100644
--- a/java/java.go
+++ b/java/java.go
@@ -379,6 +379,7 @@
 	frameworkResTag       = dependencyTag{name: "framework-res"}
 	frameworkApkTag       = dependencyTag{name: "framework-apk"}
 	kotlinStdlibTag       = dependencyTag{name: "kotlin-stdlib"}
+	kotlinAnnotationsTag  = dependencyTag{name: "kotlin-annotations"}
 	proguardRaiseTag      = dependencyTag{name: "proguard-raise"}
 	certificateTag        = dependencyTag{name: "certificate"}
 	instrumentationForTag = dependencyTag{name: "instrumentation_for"}
@@ -483,6 +484,9 @@
 		// TODO(ccross): move this to a mutator pass that can tell if generated sources contain
 		// Kotlin files
 		ctx.AddVariationDependencies(nil, kotlinStdlibTag, "kotlin-stdlib")
+		if len(j.properties.Annotation_processors) > 0 {
+			ctx.AddVariationDependencies(nil, kotlinAnnotationsTag, "kotlin-annotations")
+		}
 	}
 
 	if j.shouldInstrumentStatic(ctx) {
@@ -564,6 +568,7 @@
 	systemModules      android.Path
 	aidlPreprocess     android.OptionalPath
 	kotlinStdlib       android.Paths
+	kotlinAnnotations  android.Paths
 }
 
 func checkProducesJars(ctx android.ModuleContext, dep android.SourceFileProducer) {
@@ -723,6 +728,8 @@
 				}
 			case kotlinStdlibTag:
 				deps.kotlinStdlib = dep.HeaderJars()
+			case kotlinAnnotationsTag:
+				deps.kotlinAnnotations = dep.HeaderJars()
 			}
 
 			deps.aidlIncludeDirs = append(deps.aidlIncludeDirs, dep.AidlIncludeDirs()...)
@@ -969,9 +976,20 @@
 		kotlinSrcFiles = append(kotlinSrcFiles, uniqueSrcFiles...)
 		kotlinSrcFiles = append(kotlinSrcFiles, srcFiles.FilterByExt(".kt")...)
 
-		flags.kotlincClasspath = append(flags.kotlincClasspath, deps.bootClasspath...)
-		flags.kotlincClasspath = append(flags.kotlincClasspath, deps.kotlinStdlib...)
-		flags.kotlincClasspath = append(flags.kotlincClasspath, deps.classpath...)
+		flags.classpath = append(flags.classpath, deps.kotlinStdlib...)
+		flags.classpath = append(flags.classpath, deps.kotlinAnnotations...)
+
+		flags.kotlincClasspath = append(flags.kotlincClasspath, flags.bootClasspath...)
+		flags.kotlincClasspath = append(flags.kotlincClasspath, flags.classpath...)
+
+		if len(flags.processorPath) > 0 {
+			// Use kapt for annotation processing
+			kaptSrcJar := android.PathForModuleOut(ctx, "kapt", "kapt-sources.jar")
+			kotlinKapt(ctx, kaptSrcJar, kotlinSrcFiles, srcJars, flags)
+			srcJars = append(srcJars, kaptSrcJar)
+			// Disable annotation processing in javac, it's already been handled by kapt
+			flags.processorPath = nil
+		}
 
 		kotlinJar := android.PathForModuleOut(ctx, "kotlin", jarName)
 		kotlinCompile(ctx, kotlinJar, kotlinSrcFiles, srcJars, flags)
@@ -980,7 +998,6 @@
 		}
 
 		// Make javac rule depend on the kotlinc rule
-		flags.classpath = append(flags.classpath, deps.kotlinStdlib...)
 		flags.classpath = append(flags.classpath, kotlinJar)
 
 		// Jar kotlin classes into the final jar after javac
diff --git a/java/java_test.go b/java/java_test.go
index e16ae35..9f805bb 100644
--- a/java/java_test.go
+++ b/java/java_test.go
@@ -121,6 +121,7 @@
 		"core.current.stubs",
 		"core.platform.api.stubs",
 		"kotlin-stdlib",
+		"kotlin-annotations",
 	}
 
 	for _, extra := range extraModules {
diff --git a/java/kotlin.go b/java/kotlin.go
index 5bc7441..c72f2de 100644
--- a/java/kotlin.go
+++ b/java/kotlin.go
@@ -15,9 +15,13 @@
 package java
 
 import (
-	"android/soong/android"
+	"bytes"
+	"encoding/base64"
+	"encoding/binary"
 	"strings"
 
+	"android/soong/android"
+
 	"github.com/google/blueprint"
 )
 
@@ -26,7 +30,7 @@
 		Command: `rm -rf "$classesDir" "$srcJarDir" "$kotlinBuildFile" && mkdir -p "$classesDir" "$srcJarDir" && ` +
 			`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" $srcJars && ` +
 			`${config.GenKotlinBuildFileCmd} $classpath $classesDir $out.rsp $srcJarDir/list > $kotlinBuildFile &&` +
-			`${config.KotlincCmd} $kotlincFlags ` +
+			`${config.KotlincCmd} ${config.JavacHeapFlags} $kotlincFlags ` +
 			`-jvm-target $kotlinJvmTarget -Xbuild-file=$kotlinBuildFile && ` +
 			`${config.SoongZipCmd} -jar -o $out -C $classesDir -D $classesDir`,
 		CommandDeps: []string{
@@ -41,12 +45,11 @@
 	},
 	"kotlincFlags", "classpath", "srcJars", "srcJarDir", "classesDir", "kotlinJvmTarget", "kotlinBuildFile")
 
+// kotlinCompile takes .java and .kt sources and srcJars, and compiles the .kt sources into a classes jar in outputFile.
 func kotlinCompile(ctx android.ModuleContext, outputFile android.WritablePath,
 	srcFiles, srcJars android.Paths,
 	flags javaBuilderFlags) {
 
-	inputs := append(android.Paths(nil), srcFiles...)
-
 	var deps android.Paths
 	deps = append(deps, flags.kotlincClasspath...)
 	deps = append(deps, srcJars...)
@@ -55,7 +58,7 @@
 		Rule:        kotlinc,
 		Description: "kotlinc",
 		Output:      outputFile,
-		Inputs:      inputs,
+		Inputs:      srcFiles,
 		Implicits:   deps,
 		Args: map[string]string{
 			"classpath":       flags.kotlincClasspath.FormJavaClassPath("-classpath"),
@@ -69,3 +72,97 @@
 		},
 	})
 }
+
+var kapt = pctx.AndroidGomaStaticRule("kapt",
+	blueprint.RuleParams{
+		Command: `rm -rf "$srcJarDir" "$kotlinBuildFile" "$kaptDir" && mkdir -p "$srcJarDir" "$kaptDir" && ` +
+			`${config.ZipSyncCmd} -d $srcJarDir -l $srcJarDir/list -f "*.java" $srcJars && ` +
+			`${config.GenKotlinBuildFileCmd} $classpath "" $out.rsp $srcJarDir/list > $kotlinBuildFile &&` +
+			`${config.KotlincCmd} ${config.KotlincSuppressJDK9Warnings} ${config.JavacHeapFlags} $kotlincFlags ` +
+			`-Xplugin=${config.KotlinKaptJar} ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:sources=$kaptDir/sources ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:classes=$kaptDir/classes ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:stubs=$kaptDir/stubs ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:correctErrorTypes=true ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:aptMode=stubsAndApt ` +
+			`-P plugin:org.jetbrains.kotlin.kapt3:javacArguments=$encodedJavacFlags ` +
+			`$kaptProcessorPath ` +
+			`-Xbuild-file=$kotlinBuildFile && ` +
+			`${config.SoongZipCmd} -jar -o $out -C $kaptDir/sources -D $kaptDir/sources`,
+		CommandDeps: []string{
+			"${config.KotlincCmd}",
+			"${config.KotlinCompilerJar}",
+			"${config.KotlinKaptJar}",
+			"${config.GenKotlinBuildFileCmd}",
+			"${config.SoongZipCmd}",
+			"${config.ZipSyncCmd}",
+		},
+		Rspfile:        "$out.rsp",
+		RspfileContent: `$in`,
+	},
+	"kotlincFlags", "encodedJavacFlags", "kaptProcessorPath", "classpath", "srcJars", "srcJarDir", "kaptDir", "kotlinJvmTarget", "kotlinBuildFile")
+
+// kotlinKapt performs Kotlin-compatible annotation processing.  It takes .kt and .java sources and srcjars, and runs
+// annotation processors over all of them, producing a srcjar of generated code in outputFile.  The srcjar should be
+// added as an additional input to kotlinc and javac rules, and the javac rule should have annotation processing
+// disabled.
+func kotlinKapt(ctx android.ModuleContext, outputFile android.WritablePath,
+	srcFiles, srcJars android.Paths,
+	flags javaBuilderFlags) {
+
+	var deps android.Paths
+	deps = append(deps, flags.kotlincClasspath...)
+	deps = append(deps, srcJars...)
+	deps = append(deps, flags.processorPath...)
+
+	kaptProcessorPath := flags.processorPath.FormTurbineClasspath("-P plugin:org.jetbrains.kotlin.kapt3:apclasspath=")
+
+	encodedJavacFlags := kaptEncodeFlags([][2]string{
+		{"-source", flags.javaVersion},
+		{"-target", flags.javaVersion},
+	})
+
+	ctx.Build(pctx, android.BuildParams{
+		Rule:        kapt,
+		Description: "kapt",
+		Output:      outputFile,
+		Inputs:      srcFiles,
+		Implicits:   deps,
+		Args: map[string]string{
+			"classpath":         flags.kotlincClasspath.FormJavaClassPath("-classpath"),
+			"kotlincFlags":      flags.kotlincFlags,
+			"srcJars":           strings.Join(srcJars.Strings(), " "),
+			"srcJarDir":         android.PathForModuleOut(ctx, "kapt", "srcJars").String(),
+			"kotlinBuildFile":   android.PathForModuleOut(ctx, "kapt", "build.xml").String(),
+			"kaptProcessorPath": strings.Join(kaptProcessorPath, " "),
+			"kaptDir":           android.PathForModuleOut(ctx, "kapt/gen").String(),
+			"encodedJavacFlags": encodedJavacFlags,
+		},
+	})
+}
+
+// kapt converts a list of key, value pairs into a base64 encoded Java serialization, which is what kapt expects.
+func kaptEncodeFlags(options [][2]string) string {
+	buf := &bytes.Buffer{}
+
+	binary.Write(buf, binary.BigEndian, uint32(len(options)))
+	for _, option := range options {
+		binary.Write(buf, binary.BigEndian, uint16(len(option[0])))
+		buf.WriteString(option[0])
+		binary.Write(buf, binary.BigEndian, uint16(len(option[1])))
+		buf.WriteString(option[1])
+	}
+
+	header := &bytes.Buffer{}
+	header.Write([]byte{0xac, 0xed, 0x00, 0x05}) // java serialization header
+
+	if buf.Len() < 256 {
+		header.WriteByte(0x77) // blockdata
+		header.WriteByte(byte(buf.Len()))
+	} else {
+		header.WriteByte(0x7a) // blockdatalong
+		binary.Write(header, binary.BigEndian, uint32(buf.Len()))
+	}
+
+	return base64.StdEncoding.EncodeToString(append(header.Bytes(), buf.Bytes()...))
+}
diff --git a/java/kotlin_test.go b/java/kotlin_test.go
index 08a3085..1069f42 100644
--- a/java/kotlin_test.go
+++ b/java/kotlin_test.go
@@ -15,6 +15,7 @@
 package java
 
 import (
+	"strconv"
 	"strings"
 	"testing"
 )
@@ -80,3 +81,109 @@
 			bazHeaderJar.Output.String(), barKotlinc.Implicits.Strings())
 	}
 }
+
+func TestKapt(t *testing.T) {
+	ctx := testJava(t, `
+		java_library {
+			name: "foo",
+			srcs: ["a.java", "b.kt"],
+			annotation_processors: ["bar"],
+		}
+
+		java_library_host {
+			name: "bar",
+		}
+		`)
+
+	kapt := ctx.ModuleForTests("foo", "android_common").Rule("kapt")
+	kotlinc := ctx.ModuleForTests("foo", "android_common").Rule("kotlinc")
+	javac := ctx.ModuleForTests("foo", "android_common").Rule("javac")
+
+	// Test that the kotlin and java sources are passed to kapt and kotlinc
+	if len(kapt.Inputs) != 2 || kapt.Inputs[0].String() != "a.java" || kapt.Inputs[1].String() != "b.kt" {
+		t.Errorf(`foo kapt inputs %v != ["a.java", "b.kt"]`, kapt.Inputs)
+	}
+	if len(kotlinc.Inputs) != 2 || kotlinc.Inputs[0].String() != "a.java" || kotlinc.Inputs[1].String() != "b.kt" {
+		t.Errorf(`foo kotlinc inputs %v != ["a.java", "b.kt"]`, kotlinc.Inputs)
+	}
+
+	// Test that only the java sources are passed to javac
+	if len(javac.Inputs) != 1 || javac.Inputs[0].String() != "a.java" {
+		t.Errorf(`foo inputs %v != ["a.java"]`, javac.Inputs)
+	}
+
+	// Test that the kapt srcjar is a dependency of kotlinc and javac rules
+	if !inList(kapt.Output.String(), kotlinc.Implicits.Strings()) {
+		t.Errorf("expected %q in kotlinc implicits %v", kapt.Output.String(), kotlinc.Implicits.Strings())
+	}
+	if !inList(kapt.Output.String(), javac.Implicits.Strings()) {
+		t.Errorf("expected %q in javac implicits %v", kapt.Output.String(), javac.Implicits.Strings())
+	}
+
+	// Test that the kapt srcjar is extracted by the kotlinc and javac rules
+	if kotlinc.Args["srcJars"] != kapt.Output.String() {
+		t.Errorf("expected %q in kotlinc srcjars %v", kapt.Output.String(), kotlinc.Args["srcJars"])
+	}
+	if javac.Args["srcJars"] != kapt.Output.String() {
+		t.Errorf("expected %q in javac srcjars %v", kapt.Output.String(), kotlinc.Args["srcJars"])
+	}
+}
+
+func TestKaptEncodeFlags(t *testing.T) {
+	// Compares the kaptEncodeFlags against the results of the example implementation at
+	// https://kotlinlang.org/docs/reference/kapt.html#apjavac-options-encoding
+	tests := []struct {
+		in  [][2]string
+		out string
+	}{
+		{
+			// empty input
+			in:  [][2]string{},
+			out: "rO0ABXcEAAAAAA==",
+		},
+		{
+			// common input
+			in: [][2]string{
+				{"-source", "1.8"},
+				{"-target", "1.8"},
+			},
+			out: "rO0ABXcgAAAAAgAHLXNvdXJjZQADMS44AActdGFyZ2V0AAMxLjg=",
+		},
+		{
+			// input that serializes to a 255 byte block
+			in: [][2]string{
+				{"-source", "1.8"},
+				{"-target", "1.8"},
+				{"a", strings.Repeat("b", 218)},
+			},
+			out: "rO0ABXf/AAAAAwAHLXNvdXJjZQADMS44AActdGFyZ2V0AAMxLjgAAWEA2mJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJi",
+		},
+		{
+			// input that serializes to a 256 byte block
+			in: [][2]string{
+				{"-source", "1.8"},
+				{"-target", "1.8"},
+				{"a", strings.Repeat("b", 219)},
+			},
+			out: "rO0ABXoAAAEAAAAAAwAHLXNvdXJjZQADMS44AActdGFyZ2V0AAMxLjgAAWEA22JiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYg==",
+		},
+		{
+			// input that serializes to a 257 byte block
+			in: [][2]string{
+				{"-source", "1.8"},
+				{"-target", "1.8"},
+				{"a", strings.Repeat("b", 220)},
+			},
+			out: "rO0ABXoAAAEBAAAAAwAHLXNvdXJjZQADMS44AActdGFyZ2V0AAMxLjgAAWEA3GJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmJiYmI=",
+		},
+	}
+
+	for i, test := range tests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			got := kaptEncodeFlags(test.in)
+			if got != test.out {
+				t.Errorf("\nwant %q\n got %q", test.out, got)
+			}
+		})
+	}
+}