diff --git a/Android.bp b/Android.bp
index d5213a8..ed704ff 100644
--- a/Android.bp
+++ b/Android.bp
@@ -533,6 +533,7 @@
         "payload_generator/block_mapping.cc",
         "payload_generator/boot_img_filesystem.cc",
         "payload_generator/bzip.cc",
+        "payload_generator/cow_size_estimator.cc",
         "payload_generator/deflate_utils.cc",
         "payload_generator/delta_diff_generator.cc",
         "payload_generator/delta_diff_utils.cc",