diff --git a/android/paths.go b/android/paths.go
index 2c50104..6c3009f 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -16,7 +16,6 @@
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -2099,13 +2098,16 @@
 
 // Writes a file to the output directory.  Attempting to write directly to the output directory
 // will fail due to the sandbox of the soong_build process.
+// Only writes the file if the file doesn't exist or if it has different contents, to prevent
+// updating the timestamp if no changes would be made. (This is better for incremental
+// performance.)
 func WriteFileToOutputDir(path WritablePath, data []byte, perm os.FileMode) error {
 	absPath := absolutePath(path.String())
 	err := os.MkdirAll(filepath.Dir(absPath), 0777)
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(absPath, data, perm)
+	return pathtools.WriteFileIfChanged(absPath, data, perm)
 }
 
 func RemoveAllOutputDir(path WritablePath) error {