diff --git a/authfs/Android.bp b/authfs/Android.bp
index 8ac600d..e04d5e1 100644
--- a/authfs/Android.bp
+++ b/authfs/Android.bp
@@ -73,6 +73,7 @@
     tools: [
         "fsverity_manifest_generator",
         "fsverity",
+        "soong_zip",
     ],
     srcs: [
         "testdata/input.4k",
@@ -85,13 +86,11 @@
      * to load a generated fsverity manifest for the test input files into the
      * test VM.
      */
-    cmd: "out_dir=$$(dirname $(out))" +
-        "&& assets_dir=\"assets\" " +
-        "&& mkdir -p $$out_dir/$$assets_dir" +
+    cmd: "mkdir -p $(genDir)/assets" +
         "&& $(location fsverity_manifest_generator) " +
         "    --fsverity-path $(location fsverity) " +
         "    --base-dir $$(dirname $(in) | head -1) " +
-        "    --output $$out_dir/$$assets_dir/input_manifest.pb " +
+        "    --output $(genDir)/assets/input_manifest.pb " +
         "    $(in) " +
-        "&& jar cf $(out) -C $$out_dir $$assets_dir",
+        "&& $(location soong_zip) -jar -o $(out) -C $(genDir) -D $(genDir)/assets",
 }