diff --git a/private/install.h b/private/install.h
new file mode 100644
index 0000000..12d303b
--- /dev/null
+++ b/private/install.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Private headers exposed for testing purpose only.
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include <ziparchive/zip_archive.h>
+
+int update_binary_command(const std::string& path, ZipArchiveHandle zip, int retry_count,
+                          int status_fd, std::vector<std::string>* cmd);