diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index f49050918..0713274a6 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -4016,7 +4016,7 @@ void Blockchain::cancel()
 static const char expected_block_hashes_hash[] = "23d8a8c73de7b2383c72a016d9a6034e69d62dd48077d1c414e064ceab6daa94";
 void Blockchain::load_compiled_in_block_hashes()
 {
-  if (m_fast_sync && get_blocks_dat_start(m_testnet) != nullptr)
+  if (m_fast_sync && get_blocks_dat_start(m_testnet) != nullptr && get_blocks_dat_size(m_testnet) > 0)
   {
     MINFO("Loading precomputed blocks (" << get_blocks_dat_size(m_testnet) << " bytes)");