diff --git a/apex/Android.bp b/apex/Android.bp
index 9d4cfdf..88487e4 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -109,3 +109,20 @@
         "simg2img",
     ],
 }
+
+// custom tool to replace bytes in a file
+python_binary_host {
+    name: "replace_bytes",
+    srcs: [
+        "replace_bytes.py",
+    ],
+    version: {
+        py2: {
+            enabled: false,
+        },
+        py3: {
+            enabled: true,
+            embedded_launcher: true,
+        },
+    },
+}