diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -179,6 +179,12 @@
     virtual bool findBlock(const BlockHash &hash,
                            const FoundBlock &block = {}) = 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;
+
     //! 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
@@ -289,6 +289,18 @@
             WAIT_LOCK(cs_main, lock);
             return FillBlock(LookupBlockIndex(hash), block, lock);
         }
+        bool findAncestorByHash(const BlockHash &block_hash,
+                                const BlockHash &ancestor_hash,
+                                const FoundBlock &ancestor_out) override {
+            WAIT_LOCK(cs_main, lock);
+            const CBlockIndex *block = LookupBlockIndex(block_hash);
+            const CBlockIndex *ancestor = LookupBlockIndex(ancestor_hash);
+            if (block && ancestor &&
+                block->GetAncestor(ancestor->nHeight) != ancestor) {
+                ancestor = nullptr;
+            }
+            return FillBlock(ancestor, ancestor_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
@@ -50,4 +50,16 @@
     BOOST_CHECK(!chain->findBlock(BlockHash(), FoundBlock()));
 }
 
+BOOST_AUTO_TEST_CASE(findAncestorByHash) {
+    auto chain = interfaces::MakeChain(m_node, Params());
+    auto &active = ChainActive();
+    int height = -1;
+    BOOST_CHECK(chain->findAncestorByHash(active[20]->GetBlockHash(),
+                                          active[10]->GetBlockHash(),
+                                          FoundBlock().height(height)));
+    BOOST_CHECK_EQUAL(height, 10);
+    BOOST_CHECK(!chain->findAncestorByHash(active[10]->GetBlockHash(),
+                                           active[20]->GetBlockHash()));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -26,6 +26,8 @@
 #include <cstdint>
 #include <tuple>
 
+using interfaces::FoundBlock;
+
 static std::string EncodeDumpString(const std::string &str) {
     std::stringstream ret;
     for (const uint8_t c : str) {
@@ -425,9 +427,11 @@
     }
 
     auto locked_chain = pwallet->chain().lock();
-    Optional<int> height =
-        locked_chain->getBlockHeight(merkleBlock.header.GetHash());
-    if (height == nullopt) {
+    LOCK(pwallet->cs_wallet);
+    int height;
+    if (!pwallet->chain().findAncestorByHash(pwallet->GetLastBlockHash(),
+                                             merkleBlock.header.GetHash(),
+                                             FoundBlock().height(height))) {
         throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY,
                            "Block not found in chain");
     }
@@ -440,12 +444,10 @@
 
     size_t txnIndex = vIndex[it - vMatch.begin()];
 
-    CWalletTx::Confirmation confirm(CWalletTx::Status::CONFIRMED, *height,
+    CWalletTx::Confirmation confirm(CWalletTx::Status::CONFIRMED, height,
                                     merkleBlock.header.GetHash(), txnIndex);
     wtx.m_confirm = confirm;
 
-    LOCK(pwallet->cs_wallet);
-
     if (pwallet->IsMine(*wtx.tx)) {
         pwallet->AddToWallet(wtx, false);
         return NullUniValue;