diff --git a/cpio/Android.mk b/cpio/Android.mk
index 5184463..575beb2 100644
--- a/cpio/Android.mk
+++ b/cpio/Android.mk
@@ -8,6 +8,8 @@
 
 LOCAL_MODULE := mkbootfs
 
+LOCAL_CFLAGS := -Werror
+
 include $(BUILD_HOST_EXECUTABLE)
 
 $(call dist-for-goals,dist_files,$(LOCAL_BUILT_MODULE))
diff --git a/cpio/mkbootfs.c b/cpio/mkbootfs.c
index 7d3740c..7175749 100644
--- a/cpio/mkbootfs.c
+++ b/cpio/mkbootfs.c
@@ -78,8 +78,9 @@
         s->st_mode = empty_path_config->mode | (s->st_mode & ~07777);
     } else {
         // Use the compiled-in fs_config() function.
-
-        fs_config(path, S_ISDIR(s->st_mode), &s->st_uid, &s->st_gid, &s->st_mode, &capabilities);
+        unsigned st_mode = s->st_mode;
+        fs_config(path, S_ISDIR(s->st_mode), &s->st_uid, &s->st_gid, &st_mode, &capabilities);
+        s->st_mode = (typeof(s->st_mode)) st_mode;
     }
 }