diff --git a/system/update_engine/payload_generator/generate_delta_main.cc b/system/update_engine/payload_generator/generate_delta_main.cc
index 6861705b58e..66d763c9602 100644
--- a/system/update_engine/payload_generator/generate_delta_main.cc
+++ b/system/update_engine/payload_generator/generate_delta_main.cc
@@ -465,8 +465,9 @@ void RoundDownPartitions(const ImageConfig& config) {
     if (part.path.empty()) {
       continue;
     }
-    const auto size = std::max<size_t>(utils::FileSize(part.path), kBlockSize);
+    auto size = utils::FileSize(part.path);
     if (size % kBlockSize != 0) {
+      size = std::max<size_t>(size, kBlockSize);
       const auto err =
           truncate(part.path.c_str(), size / kBlockSize * kBlockSize);
       CHECK_EQ(err, 0) << "Failed to truncate " << part.path << ", error "