diff --git a/services/incremental/IncrementalService.h b/services/incremental/IncrementalService.h
index 8dc789f..a8434af 100644
--- a/services/incremental/IncrementalService.h
+++ b/services/incremental/IncrementalService.h
@@ -472,6 +472,7 @@
                                StorageLoadingProgressListener&& progressListener);
 
     void trimReservedSpaceV1(const IncFsMount& ifs);
+    int64_t elapsedUsSinceMonoTs(uint64_t monoTsUs);
 
 private:
     const std::unique_ptr<VoldServiceWrapper> mVold;