diff --git a/doc/release-notes.md b/doc/release-notes.md
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -5,3 +5,9 @@
   <https://download.bitcoinabc.org/0.22.5/>
 
 This release includes the following features and fixes:
+
+Updated RPCs
+------------
+
+- The `getchaintxstats` RPC now returns the additional key of
+  `window_final_block_height`.
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1912,6 +1912,8 @@
             "number of transactions in the chain up to that point.\n"
             "  \"window_final_block_hash\": \"...\",    (string) The hash of "
             "the final block in the window.\n"
+            "  \"window_final_block_height\": xxxxx,    (numeric) The height "
+            "of the final block in the window.\n"
             "  \"window_block_count\": xxxxx,           (numeric) Size of the "
             "window in number of blocks.\n"
             "  \"window_tx_count\": xxxxx,              (numeric) The number "
@@ -1976,6 +1978,7 @@
     ret.pushKV("time", pindex->GetBlockTime());
     ret.pushKV("txcount", pindex->GetChainTxCount());
     ret.pushKV("window_final_block_hash", pindex->GetBlockHash().GetHex());
+    ret.pushKV("window_final_block_height", pindex->nHeight);
     ret.pushKV("window_block_count", blockcount);
     if (blockcount > 0) {
         ret.pushKV("window_tx_count", nTxDiff);
diff --git a/test/functional/rpc_blockchain.py b/test/functional/rpc_blockchain.py
--- a/test/functional/rpc_blockchain.py
+++ b/test/functional/rpc_blockchain.py
@@ -213,6 +213,7 @@
         assert_equal(chaintxstats['time'], b200['time'])
         assert_equal(chaintxstats['txcount'], 201)
         assert_equal(chaintxstats['window_final_block_hash'], b200_hash)
+        assert_equal(chaintxstats['window_final_block_height'], 200)
         assert_equal(chaintxstats['window_block_count'], 199)
         assert_equal(chaintxstats['window_tx_count'], 199)
         assert_equal(chaintxstats['window_interval'], time_diff)
@@ -223,6 +224,7 @@
         assert_equal(chaintxstats['time'], b1['time'])
         assert_equal(chaintxstats['txcount'], 2)
         assert_equal(chaintxstats['window_final_block_hash'], b1_hash)
+        assert_equal(chaintxstats['window_final_block_height'], 1)
         assert_equal(chaintxstats['window_block_count'], 0)
         assert 'window_tx_count' not in chaintxstats
         assert 'window_interval' not in chaintxstats