diff --git a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
index 871ed27..9e7cf7a2 100644
--- a/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
+++ b/fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.h
@@ -82,7 +82,7 @@
                                                  CowOperationType type);
     size_t GetCompressionFactor(const size_t blocks_to_compress, CowOperationType type) const;
 
-    constexpr bool IsBlockAligned(const size_t size) {
+    constexpr bool IsBlockAligned(const uint64_t size) {
         // These are the only block size supported. Block size beyond 256k
         // may impact random read performance post OTA boot.
         const size_t values[] = {4_KiB, 8_KiB, 16_KiB, 32_KiB, 64_KiB, 128_KiB, 256_KiB};
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.h b/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.h
index 04b2736..378d809 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.h
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.h
@@ -57,7 +57,7 @@
     bool ReadFromSourceDevice(const CowOperation* cow_op, void* buffer);
     bool ReadDataFromBaseDevice(sector_t sector, void* buffer, size_t read_size);
 
-    constexpr bool IsBlockAligned(size_t size) { return ((size & (BLOCK_SZ - 1)) == 0); }
+    constexpr bool IsBlockAligned(uint64_t size) { return ((size & (BLOCK_SZ - 1)) == 0); }
     constexpr sector_t ChunkToSector(chunk_t chunk) { return chunk << CHUNK_SHIFT; }
     constexpr chunk_t SectorToChunk(sector_t sector) { return sector >> CHUNK_SHIFT; }