diff --git a/table/format.cc b/table/format.cc
index ae998c1f30..faf71f6ee4 100644
--- a/table/format.cc
+++ b/table/format.cc
@@ -33,7 +33,7 @@ void Footer::EncodeTo(std::string* dst) const {
   const size_t original_size = dst->size();
   metaindex_handle_.EncodeTo(dst);
   index_handle_.EncodeTo(dst);
-  dst->resize(2 * BlockHandle::kMaxEncodedLength);  // Padding
+  dst->resize(original_size + 2 * BlockHandle::kMaxEncodedLength);  // Padding
   PutFixed32(dst, static_cast<uint32_t>(kTableMagicNumber & 0xffffffffu));
   PutFixed32(dst, static_cast<uint32_t>(kTableMagicNumber >> 32));
   assert(dst->size() == original_size + kEncodedLength);