diff --git a/src/txdb.cpp b/src/txdb.cpp
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -5,7 +5,6 @@
 
 #include <txdb.h>
 
-#include <blockdb.h>
 #include <chain.h>
 #include <node/ui_interface.h>
 #include <pow/pow.h>
@@ -463,6 +462,9 @@
 }
 
 bool CBlockTreeDB::Upgrade(const Consensus::Params &params) {
+    // This method used to add the block size to pre-0.22.8 block index
+    // databases. This is no longer supported as of 0.25.5, but the method is
+    // kept to update the version number in the database.
     std::unique_ptr<CDBIterator> pcursor(NewIterator());
 
     uint64_t version = 0;
@@ -476,92 +478,22 @@
         return true;
     }
 
-    CDBBatch batch(*this);
-
     pcursor->Seek(std::make_pair(DB_BLOCK_INDEX, uint256()));
-    if (!pcursor->Valid()) {
-        // The DB is empty, so just write the version number and consider the
-        // upgrade done.
-        batch.Write("version", uint64_t(CLIENT_VERSION));
-        WriteBatch(batch);
-        return true;
-    }
-
-    int64_t count = 0;
-    LogPrintf("Upgrading block index database...\n");
-    int reportDone = -1;
-    std::pair<uint8_t, uint256> key = {DB_BLOCK_INDEX, uint256()};
-    while (pcursor->Valid()) {
-        if (ShutdownRequested()) {
-            break;
-        }
-
-        if (!pcursor->GetKey(key) || key.first != DB_BLOCK_INDEX) {
-            break;
-        }
-
-        if (count++ % 256 == 0) {
-            uint32_t high =
-                0x100 * *key.second.begin() + *(key.second.begin() + 1);
-            int percentageDone = (int)(high * 100.0 / 65536.0 + 0.5);
-            uiInterface.ShowProgress(
-                _("Upgrading block index database").translated, percentageDone,
-                true);
-            if (reportDone < percentageDone / 10) {
-                // report max. every 10% step
-                LogPrintfToBeContinued("[%d%%]...", percentageDone);
-                reportDone = percentageDone / 10;
-            }
-        }
-
-        // Read the block index entry and update it.
-        CDiskBlockIndex diskindex;
-        if (!pcursor->GetValue(diskindex)) {
-            return error("%s: cannot parse CDiskBlockIndex record", __func__);
-        }
-
-        // The block hash needs to be usable.
-        BlockHash blockhash = diskindex.GetBlockHash();
-        diskindex.phashBlock = &blockhash;
-
-        bool mustUpdate = false;
-
-        // We must update the block index to add the size.
-        if (CLIENT_VERSION >= CDiskBlockIndex::TRACK_SIZE_VERSION &&
-            version < CDiskBlockIndex::TRACK_SIZE_VERSION &&
-            diskindex.nTx > 0 && diskindex.nSize == 0) {
-            if (!diskindex.nStatus.hasData()) {
-                // The block was pruned, we need a full reindex.
-                LogPrintf("\nThe block %s is pruned. The block index cannot be "
-                          "upgraded and reindexing is required.\n",
-                          blockhash.GetHex());
-                return false;
-            }
-
-            CBlock block;
-            if (!ReadBlockFromDisk(block, &diskindex, params)) {
-                // Failed to read the block from disk, even though it is marked
-                // that we have data for this block.
-                return false;
-            }
 
-            mustUpdate = true;
-            diskindex.nSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
-        }
-
-        if (mustUpdate) {
-            batch.Write(std::make_pair(DB_BLOCK_INDEX, blockhash), diskindex);
-        }
-
-        pcursor->Next();
+    // The DB is not empty, and the version is either non-existent or too old.
+    // The node requires a reindex.
+    if (pcursor->Valid() && version < CDiskBlockIndex::TRACK_SIZE_VERSION) {
+        LogPrintf(
+            "\nThe database is too old. The block index cannot be upgraded "
+            "and reindexing is required.\n");
+        return false;
     }
 
-    // Upgrade is done, now let's update the version number.
+    // The DB is empty or recent enough.
+    // Just write the new version number and consider the upgrade done.
+    CDBBatch batch(*this);
+    LogPrintf("Updating the block index database version to %d\n",
+              CLIENT_VERSION);
     batch.Write("version", uint64_t(CLIENT_VERSION));
-
-    WriteBatch(batch);
-    CompactRange({DB_BLOCK_INDEX, uint256()}, key);
-    uiInterface.ShowProgress("", 100, false);
-    LogPrintf("[%s].\n", ShutdownRequested() ? "CANCELLED" : "DONE");
-    return !ShutdownRequested();
+    return WriteBatch(batch);
 }