diff --git a/java/builder.go b/java/builder.go
index e1a912b..a48e8b1 100644
--- a/java/builder.go
+++ b/java/builder.go
@@ -148,15 +148,16 @@
 }
 
 type javaBuilderFlags struct {
-	javacFlags    string
-	bootClasspath classpath
-	classpath     classpath
-	processorPath classpath
-	processor     string
-	systemModules classpath
-	aidlFlags     string
-	aidlDeps      android.Paths
-	javaVersion   string
+	javacFlags        string
+	bootClasspath     classpath
+	classpath         classpath
+	processorPath     classpath
+	processor         string
+	systemModules     classpath
+	systemModulesDeps android.Paths
+	aidlFlags         string
+	aidlDeps          android.Paths
+	javaVersion       string
 
 	errorProneExtraJavacFlags string
 	errorProneProcessorPath   classpath
@@ -248,7 +249,7 @@
 
 	var bootClasspath string
 	if flags.javaVersion == "1.9" {
-		deps = append(deps, flags.systemModules...)
+		deps = append(deps, flags.systemModulesDeps...)
 		bootClasspath = flags.systemModules.FormJavaSystemModulesPath("--system=", ctx.Device())
 	} else {
 		deps = append(deps, flags.bootClasspath...)
@@ -430,7 +431,7 @@
 	if len(*x) > 1 {
 		panic("more than one system module")
 	} else if len(*x) == 1 {
-		return optName + strings.TrimSuffix((*x)[0].String(), "lib/modules")
+		return optName + (*x)[0].String()
 	} else if forceEmpty {
 		return optName + "none"
 	} else {
diff --git a/java/droiddoc.go b/java/droiddoc.go
index a8cf1c0..be1b281 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -692,10 +692,11 @@
 				panic("Found two system module dependencies")
 			}
 			sm := module.(*SystemModules)
-			if sm.outputFile == nil {
+			if sm.outputDir == nil && len(sm.outputDeps) == 0 {
 				panic("Missing directory for system module dependency")
 			}
-			deps.systemModules = sm.outputFile
+			deps.systemModules = sm.outputDir
+			deps.systemModulesDeps = sm.outputDeps
 		}
 	})
 	// do not pass exclude_srcs directly when expanding srcFiles since exclude_srcs
@@ -776,6 +777,7 @@
 		if deps.systemModules != nil {
 			systemModules = append(systemModules, deps.systemModules)
 		}
+		implicits = append(implicits, deps.systemModulesDeps...)
 		bootClasspathArgs = systemModules.FormJavaSystemModulesPath("--system ", ctx.Device())
 		bootClasspathArgs = bootClasspathArgs + " --patch-module java.base=."
 	}
diff --git a/java/java.go b/java/java.go
index 4b38451..a2e9ab0 100644
--- a/java/java.go
+++ b/java/java.go
@@ -628,6 +628,7 @@
 	srcs               android.Paths
 	srcJars            android.Paths
 	systemModules      android.Path
+	systemModulesDeps  android.Paths
 	aidlPreprocess     android.OptionalPath
 	kotlinStdlib       android.Paths
 	kotlinAnnotations  android.Paths
@@ -835,10 +836,11 @@
 					panic("Found two system module dependencies")
 				}
 				sm := module.(*SystemModules)
-				if sm.outputFile == nil {
+				if sm.outputDir == nil || len(sm.outputDeps) == 0 {
 					panic("Missing directory for system module dependency")
 				}
-				deps.systemModules = sm.outputFile
+				deps.systemModules = sm.outputDir
+				deps.systemModulesDeps = sm.outputDeps
 			}
 		}
 	})
@@ -968,6 +970,7 @@
 	// systemModules
 	if deps.systemModules != nil {
 		flags.systemModules = append(flags.systemModules, deps.systemModules)
+		flags.systemModulesDeps = append(flags.systemModulesDeps, deps.systemModulesDeps...)
 	}
 
 	// aidl flags.
diff --git a/java/sdk_test.go b/java/sdk_test.go
index 915333e..953c372 100644
--- a/java/sdk_test.go
+++ b/java/sdk_test.go
@@ -254,7 +254,7 @@
 			if testcase.system == "none" {
 				system = "--system=none"
 			} else if testcase.system != "" {
-				system = "--system=" + filepath.Join(buildDir, ".intermediates", testcase.system, "android_common", "system") + "/"
+				system = "--system=" + filepath.Join(buildDir, ".intermediates", testcase.system, "android_common", "system")
 			}
 
 			checkClasspath := func(t *testing.T, ctx *android.TestContext) {
diff --git a/java/system_modules.go b/java/system_modules.go
index 5a86f3c..f71f452 100644
--- a/java/system_modules.go
+++ b/java/system_modules.go
@@ -61,7 +61,7 @@
 		"moduleName", "classpath", "outDir", "workDir")
 )
 
-func TransformJarsToSystemModules(ctx android.ModuleContext, moduleName string, jars android.Paths) android.WritablePath {
+func TransformJarsToSystemModules(ctx android.ModuleContext, moduleName string, jars android.Paths) (android.Path, android.Paths) {
 	outDir := android.PathForModuleOut(ctx, "system")
 	workDir := android.PathForModuleOut(ctx, "modules")
 	outputFile := android.PathForModuleOut(ctx, "system/lib/modules")
@@ -84,7 +84,7 @@
 		},
 	})
 
-	return outputFile
+	return outDir, outputs.Paths()
 }
 
 func SystemModulesFactory() android.Module {
@@ -101,7 +101,8 @@
 
 	properties SystemModulesProperties
 
-	outputFile android.Path
+	outputDir  android.Path
+	outputDeps android.Paths
 }
 
 type SystemModulesProperties struct {
@@ -117,7 +118,7 @@
 		jars = append(jars, dep.HeaderJars()...)
 	})
 
-	system.outputFile = TransformJarsToSystemModules(ctx, "java.base", jars)
+	system.outputDir, system.outputDeps = TransformJarsToSystemModules(ctx, "java.base", jars)
 }
 
 func (system *SystemModules) DepsMutator(ctx android.BottomUpMutatorContext) {
@@ -127,16 +128,22 @@
 func (system *SystemModules) AndroidMk() android.AndroidMkData {
 	return android.AndroidMkData{
 		Custom: func(w io.Writer, name, prefix, moduleDir string, data android.AndroidMkData) {
-			makevar := "SOONG_SYSTEM_MODULES_" + name
 			fmt.Fprintln(w)
-			fmt.Fprintln(w, makevar, ":=", system.outputFile.String())
-			fmt.Fprintln(w, ".KATI_READONLY", ":=", makevar)
+
+			makevar := "SOONG_SYSTEM_MODULES_" + name
+			fmt.Fprintln(w, makevar, ":=$=", system.outputDir.String())
+			fmt.Fprintln(w)
+
+			makevar = "SOONG_SYSTEM_MODULES_LIBS_" + name
+			fmt.Fprintln(w, makevar, ":=$=", strings.Join(system.properties.Libs, " "))
+			fmt.Fprintln(w)
+
+			makevar = "SOONG_SYSTEM_MODULE_DEPS_" + name
+			fmt.Fprintln(w, makevar, ":=$=", strings.Join(system.outputDeps.Strings(), " "))
+			fmt.Fprintln(w)
+
 			fmt.Fprintln(w, name+":", "$("+makevar+")")
 			fmt.Fprintln(w, ".PHONY:", name)
-			fmt.Fprintln(w)
-			makevar = "SOONG_SYSTEM_MODULES_LIBS_" + name
-			fmt.Fprintln(w, makevar, ":=", strings.Join(system.properties.Libs, " "))
-			fmt.Fprintln(w, ".KATI_READONLY :=", makevar)
 		},
 	}
 }