diff --git a/java/builder.go b/java/builder.go
index 118f239..8992f68 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -126,6 +126,7 @@
 	dxFlags       string
 	bootClasspath classpath
 	classpath     classpath
+	systemModules classpath
 	desugarFlags  string
 	aidlFlags     string
 	javaVersion   string
@@ -177,7 +178,16 @@
 	}
 
 	deps = append(deps, srcFileLists...)
-	deps = append(deps, flags.bootClasspath...)
+
+	var bootClasspath string
+	if flags.javaVersion == "1.9" {
+		deps = append(deps, flags.systemModules...)
+		bootClasspath = flags.systemModules.JavaSystemModules(ctx.Device())
+	} else {
+		deps = append(deps, flags.bootClasspath...)
+		bootClasspath = flags.bootClasspath.JavaBootClasspath(ctx.Device())
+	}
+
 	deps = append(deps, flags.classpath...)
 
 	ctx.ModuleBuild(pctx, android.ModuleBuildParams{
@@ -188,7 +198,7 @@
 		Implicits:   deps,
 		Args: map[string]string{
 			"javacFlags":    javacFlags,
-			"bootClasspath": flags.bootClasspath.JavaBootClasspath(ctx.Device()),
+			"bootClasspath": bootClasspath,
 			"classpath":     flags.classpath.JavaClasspath(),
 			"outDir":        android.PathForModuleOut(ctx, "classes"+suffix).String(),
 			"annoDir":       android.PathForModuleOut(ctx, "anno"+suffix).String(),
@@ -259,7 +269,7 @@
 	dumpDir := android.PathForModuleOut(ctx, "desugar_dumped_classes")
 
 	javaFlags := ""
-	if ctx.AConfig().Getenv("EXPERIMENTAL_USE_OPENJDK9") != "" {
+	if ctx.AConfig().UseOpenJDK9() {
 		javaFlags = "--add-opens java.base/java.lang.invoke=ALL-UNNAMED"
 	}
 
@@ -359,6 +369,21 @@
 	}
 }
 
+// Returns a --system argument in the form javac expects with -source 1.9.  If forceEmpty is true,
+// returns --system=none if the list is empty to ensure javac does not fall back to the default
+// system modules.
+func (x *classpath) JavaSystemModules(forceEmpty bool) string {
+	if len(*x) > 1 {
+		panic("more than one system module")
+	} else if len(*x) == 1 {
+		return "--system=" + strings.TrimSuffix((*x)[0].String(), "lib/modules")
+	} else if forceEmpty {
+		return "--system=none"
+	} else {
+		return ""
+	}
+}
+
 func (x *classpath) DesugarBootClasspath() []string {
 	if x == nil || *x == nil {
 		return nil