diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -175,12 +175,26 @@
     virtual bool findBlock(const BlockHash &hash,
                            const FoundBlock &block = {}) = 0;
 
+    //! Find ancestor of block at specified height and optionally return
+    //! ancestor information.
+    virtual bool findAncestorByHeight(const BlockHash &block_hash,
+                                      int ancestor_height,
+                                      const FoundBlock &ancestor_out = {}) = 0;
+
     //! Return whether block descends from a specified ancestor, and
     //! optionally return ancestor information.
     virtual bool findAncestorByHash(const BlockHash &block_hash,
                                     const BlockHash &ancestor_hash,
                                     const FoundBlock &ancestor_out = {}) = 0;
 
+    //! Find most recent common ancestor between two blocks and optionally
+    //! return block information.
+    virtual bool findCommonAncestor(const BlockHash &block_hash1,
+                                    const BlockHash &block_hash2,
+                                    const FoundBlock &ancestor_out = {},
+                                    const FoundBlock &block1_out = {},
+                                    const FoundBlock &block2_out = {}) = 0;
+
     //! Look up unspent output information. Returns coins in the mempool and in
     //! the current chain UTXO set. Iterates through all the keys in the map and
     //! populates the values.
diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -283,6 +283,18 @@
             WAIT_LOCK(cs_main, lock);
             return FillBlock(LookupBlockIndex(hash), block, lock);
         }
+        bool findAncestorByHeight(const BlockHash &block_hash,
+                                  int ancestor_height,
+                                  const FoundBlock &ancestor_out) override {
+            WAIT_LOCK(cs_main, lock);
+            if (const CBlockIndex *block = LookupBlockIndex(block_hash)) {
+                if (const CBlockIndex *ancestor =
+                        block->GetAncestor(ancestor_height)) {
+                    return FillBlock(ancestor, ancestor_out, lock);
+                }
+            }
+            return FillBlock(nullptr, ancestor_out, lock);
+        }
         bool findAncestorByHash(const BlockHash &block_hash,
                                 const BlockHash &ancestor_hash,
                                 const FoundBlock &ancestor_out) override {
@@ -295,6 +307,20 @@
             }
             return FillBlock(ancestor, ancestor_out, lock);
         }
+        bool findCommonAncestor(const BlockHash &block_hash1,
+                                const BlockHash &block_hash2,
+                                const FoundBlock &ancestor_out,
+                                const FoundBlock &block1_out,
+                                const FoundBlock &block2_out) override {
+            WAIT_LOCK(cs_main, lock);
+            const CBlockIndex *block1 = LookupBlockIndex(block_hash1);
+            const CBlockIndex *block2 = LookupBlockIndex(block_hash2);
+            const CBlockIndex *ancestor =
+                block1 && block2 ? LastCommonAncestor(block1, block2) : nullptr;
+            return FillBlock(ancestor, ancestor_out, lock) &
+                   FillBlock(block1, block1_out, lock) &
+                   FillBlock(block2, block2_out, lock);
+        }
         void findCoins(std::map<COutPoint, Coin> &coins) override {
             return FindCoins(coins);
         }
diff --git a/src/test/interfaces_tests.cpp b/src/test/interfaces_tests.cpp
--- a/src/test/interfaces_tests.cpp
+++ b/src/test/interfaces_tests.cpp
@@ -3,7 +3,10 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <chainparams.h>
+#include <config.h>
+#include <consensus/validation.h>
 #include <interfaces/chain.h>
+#include <script/standard.h>
 #include <test/util/setup_common.h>
 #include <validation.h>
 
@@ -50,6 +53,16 @@
     BOOST_CHECK(!chain->findBlock(BlockHash(), FoundBlock()));
 }
 
+BOOST_AUTO_TEST_CASE(findAncestorByHeight) {
+    auto chain = interfaces::MakeChain(m_node, Params());
+    auto &active = ChainActive();
+    BlockHash hash;
+    BOOST_CHECK(chain->findAncestorByHeight(active[20]->GetBlockHash(), 10,
+                                            FoundBlock().hash(hash)));
+    BOOST_CHECK_EQUAL(hash, active[10]->GetBlockHash());
+    BOOST_CHECK(!chain->findAncestorByHeight(active[10]->GetBlockHash(), 20));
+}
+
 BOOST_AUTO_TEST_CASE(findAncestorByHash) {
     auto chain = interfaces::MakeChain(m_node, Params());
     auto &active = ChainActive();
@@ -62,4 +75,31 @@
                                            active[20]->GetBlockHash()));
 }
 
+BOOST_AUTO_TEST_CASE(findCommonAncestor) {
+    auto chain = interfaces::MakeChain(m_node, Params());
+    auto &active = ChainActive();
+    auto *orig_tip = active.Tip();
+    for (int i = 0; i < 10; ++i) {
+        BlockValidationState state;
+        ChainstateActive().InvalidateBlock(GetConfig(), state, active.Tip());
+    }
+    BOOST_CHECK_EQUAL(active.Height(), orig_tip->nHeight - 10);
+    coinbaseKey.MakeNewKey(true);
+    for (int i = 0; i < 20; ++i) {
+        CreateAndProcessBlock({},
+                              GetScriptForRawPubKey(coinbaseKey.GetPubKey()));
+    }
+    BOOST_CHECK_EQUAL(active.Height(), orig_tip->nHeight + 10);
+    BlockHash fork_hash;
+    int fork_height;
+    int orig_height;
+    BOOST_CHECK(chain->findCommonAncestor(
+        orig_tip->GetBlockHash(), active.Tip()->GetBlockHash(),
+        FoundBlock().height(fork_height).hash(fork_hash),
+        FoundBlock().height(orig_height)));
+    BOOST_CHECK_EQUAL(orig_height, orig_tip->nHeight);
+    BOOST_CHECK_EQUAL(fork_height, orig_tip->nHeight - 10);
+    BOOST_CHECK_EQUAL(fork_hash, active[fork_height]->GetBlockHash());
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1870,8 +1870,12 @@
     BlockHash blockId;
     if (!request.params[0].isNull() && !request.params[0].get_str().empty()) {
         blockId = BlockHash(ParseHashV(request.params[0], "blockhash"));
-        height = locked_chain->findFork(blockId, &altheight);
-        if (!height) {
+        height.emplace();
+        altheight.emplace();
+        if (!pwallet->chain().findCommonAncestor(
+                blockId, pwallet->GetLastBlockHash(),
+                /* ancestor out */ FoundBlock().height(*height),
+                /* blockId out */ FoundBlock().height(*altheight))) {
             throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
         }
     }
@@ -1891,8 +1895,7 @@
     bool include_removed =
         (request.params[3].isNull() || request.params[3].get_bool());
 
-    const Optional<int> tip_height = locked_chain->getHeight();
-    int depth = tip_height && height ? (1 + *tip_height - *height) : -1;
+    int depth = height ? pwallet->GetLastBlockHeight() + 1 - *height : -1;
 
     UniValue transactions(UniValue::VARR);
 
@@ -1930,10 +1933,11 @@
         --*altheight;
     }
 
-    int last_height = tip_height ? *tip_height + 1 - target_confirms : -1;
-    BlockHash lastblock = last_height >= 0
-                              ? locked_chain->getBlockHash(last_height)
-                              : BlockHash();
+    BlockHash lastblock;
+    CHECK_NONFATAL(pwallet->chain().findAncestorByHeight(
+        pwallet->GetLastBlockHash(),
+        pwallet->GetLastBlockHeight() + 1 - target_confirms,
+        FoundBlock().hash(lastblock)));
 
     UniValue ret(UniValue::VOBJ);
     ret.pushKV("transactions", transactions);