diff --git a/android/config.go b/android/config.go
index b906108..58a1dd2 100644
--- a/android/config.go
+++ b/android/config.go
@@ -93,8 +93,9 @@
 
 	deviceConfig *deviceConfig
 
-	srcDir   string // the path of the root source directory
-	buildDir string // the path of the build output directory
+	srcDir         string // the path of the root source directory
+	buildDir       string // the path of the build output directory
+	moduleListFile string // the path to the file which lists blueprint files to parse.
 
 	env       map[string]string
 	envLock   sync.Mutex
@@ -316,7 +317,7 @@
 
 // New creates a new Config object.  The srcDir argument specifies the path to
 // the root source directory. It also loads the config file, if found.
-func NewConfig(srcDir, buildDir string) (Config, error) {
+func NewConfig(srcDir, buildDir string, moduleListFile string) (Config, error) {
 	// Make a config with default options
 	config := &config{
 		ConfigFileName:           filepath.Join(buildDir, configFileName),
@@ -328,7 +329,8 @@
 		buildDir:          buildDir,
 		multilibConflicts: make(map[ArchType]bool),
 
-		fs: pathtools.NewOsFs(absSrcDir),
+		moduleListFile: moduleListFile,
+		fs:             pathtools.NewOsFs(absSrcDir),
 	}
 
 	config.deviceConfig = &deviceConfig{
diff --git a/android/paths.go b/android/paths.go
index bed6f3f..724bbd0 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -904,6 +904,27 @@
 var _ Path = OutputPath{}
 var _ WritablePath = OutputPath{}
 
+// toolDepPath is a Path representing a dependency of the build tool.
+type toolDepPath struct {
+	basePath
+}
+
+var _ Path = toolDepPath{}
+
+// pathForBuildToolDep joins the provided paths and returns a toolDepPath that
+// is validated to not contain invalid characters.
+// There is no validation for the base directory of the constructed path.
+// Only use this function to construct paths for depenencies of the build
+// tool invocation.
+// On error, it will return a usable, but invalid toolDepPath, and report a ModuleError.
+func pathForBuildToolDep(ctx PathContext, pathComponents ...string) toolDepPath {
+	path, err := validatePath(pathComponents...)
+	if err != nil {
+		reportPathError(ctx, err)
+	}
+	return toolDepPath{basePath{path, ctx.Config(), ""}}
+}
+
 // PathForOutput joins the provided paths and returns an OutputPath that is
 // validated to not escape the build dir.
 // On error, it will return a usable, but invalid OutputPath, and report a ModuleError.
diff --git a/android/writedocs.go b/android/writedocs.go
index 9e43e80..4eb15e6 100644
--- a/android/writedocs.go
+++ b/android/writedocs.go
@@ -44,6 +44,10 @@
 }
 
 func (c *docsSingleton) GenerateBuildActions(ctx SingletonContext) {
+	var deps Paths
+	deps = append(deps, pathForBuildToolDep(ctx, ctx.Config().moduleListFile))
+	deps = append(deps, pathForBuildToolDep(ctx, ctx.Config().ProductVariablesFileName))
+
 	// Generate build system docs for the primary builder.  Generating docs reads the source
 	// files used to build the primary builder, but that dependency will be picked up through
 	// the dependency on the primary builder itself.  There are no dependencies on the
@@ -63,6 +67,7 @@
 	ctx.Build(pctx, BuildParams{
 		Rule:   soongDocs,
 		Output: docsFile,
+		Inputs: deps,
 		Args: map[string]string{
 			"outDir": PathForOutput(ctx, "docs").String(),
 		},