diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1734,20 +1734,22 @@
             "ends the window.\n"
             "\nResult:\n"
             "{\n"
-            "  \"time\": xxxxx,                (numeric) The timestamp for the "
-            "final block in the window in UNIX format.\n"
-            "  \"txcount\": xxxxx,             (numeric) The total number of "
-            "transactions in the chain up to that point.\n"
-            "  \"window_block_count\": xxxxx,  (numeric) Size of the window in "
-            "number of blocks.\n"
-            "  \"window_tx_count\": xxxxx,     (numeric) The number of "
-            "transactions in the window. Only returned if "
+            "  \"time\": xxxxx,                         (numeric) The "
+            "timestamp for the final block in the window in UNIX format.\n"
+            "  \"txcount\": xxxxx,                      (numeric) The total "
+            "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_block_count\": xxxxx,           (numeric) Size of "
+            "the window in number of blocks.\n"
+            "  \"window_tx_count\": xxxxx,              (numeric) The number "
+            "of transactions in the window. Only returned if "
             "\"window_block_count\" is > 0.\n"
-            "  \"window_interval\": xxxxx,     (numeric) The elapsed time in "
-            "the window in seconds. Only returned if \"window_block_count\" is "
-            "> 0.\n"
-            "  \"txrate\": x.xx,               (numeric) The average rate of "
-            "transactions per second in the window. Only returned if "
+            "  \"window_interval\": xxxxx,              (numeric) The elapsed "
+            "time in the window in seconds. Only returned if "
+            "\"window_block_count\" is > 0.\n"
+            "  \"txrate\": x.xx,                        (numeric) The average "
+            "rate of transactions per second in the window. Only returned if "
             "\"window_interval\" is > 0.\n"
             "}\n"
             "\nExamples:\n" +
@@ -1809,6 +1811,7 @@
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("time", int64_t(pindex->nTime));
     ret.pushKV("txcount", int64_t(pindex->nChainTx));
+    ret.pushKV("window_final_block_hash", pindex->GetBlockHash().GetHex());
     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
@@ -77,6 +77,8 @@
         assert_equal(sorted(res.keys()), keys)
 
     def _test_getchaintxstats(self):
+        self.log.info("Test getchaintxstats")
+
         chaintxstats = self.nodes[0].getchaintxstats(1)
         # 200 txs plus genesis tx
         assert_equal(chaintxstats['txcount'], 201)
@@ -84,22 +86,26 @@
         # we have to round because of binary math
         assert_equal(round(chaintxstats['txrate'] * 600, 10), Decimal(1))
 
-        b1 = self.nodes[0].getblock(self.nodes[0].getblockhash(1))
-        b200 = self.nodes[0].getblock(self.nodes[0].getblockhash(200))
+        b1_hash = self.nodes[0].getblockhash(1)
+        b1 = self.nodes[0].getblock(b1_hash)
+        b200_hash = self.nodes[0].getblockhash(200)
+        b200 = self.nodes[0].getblock(b200_hash)
         time_diff = b200['mediantime'] - b1['mediantime']
 
         chaintxstats = self.nodes[0].getchaintxstats()
         assert_equal(chaintxstats['time'], b200['time'])
         assert_equal(chaintxstats['txcount'], 201)
+        assert_equal(chaintxstats['window_final_block_hash'], b200_hash)
         assert_equal(chaintxstats['window_block_count'], 199)
         assert_equal(chaintxstats['window_tx_count'], 199)
         assert_equal(chaintxstats['window_interval'], time_diff)
         assert_equal(
             round(chaintxstats['txrate'] * time_diff, 10), Decimal(199))
 
-        chaintxstats = self.nodes[0].getchaintxstats(blockhash=b1['hash'])
+        chaintxstats = self.nodes[0].getchaintxstats(blockhash=b1_hash)
         assert_equal(chaintxstats['time'], b1['time'])
         assert_equal(chaintxstats['txcount'], 2)
+        assert_equal(chaintxstats['window_final_block_hash'], b1_hash)
         assert_equal(chaintxstats['window_block_count'], 0)
         assert('window_tx_count' not in chaintxstats)
         assert('window_interval' not in chaintxstats)