diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 75a404c50a1..22a95f96822 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -162,6 +162,7 @@ BITCOIN_TESTS =\
 
 if ENABLE_WALLET
 BITCOIN_TESTS += \
+  wallet/test/feebumper_tests.cpp \
   wallet/test/psbt_wallet_tests.cpp \
   wallet/test/spend_tests.cpp \
   wallet/test/wallet_tests.cpp \
diff --git a/src/wallet/test/feebumper_tests.cpp b/src/wallet/test/feebumper_tests.cpp
new file mode 100644
index 00000000000..6add86dc3d1
--- /dev/null
+++ b/src/wallet/test/feebumper_tests.cpp
@@ -0,0 +1,54 @@
+// Copyright (c) 2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or https://www.opensource.org/licenses/mit-license.php.
+
+#include <primitives/transaction.h>
+#include <script/script.h>
+#include <util/strencodings.h>
+#include <wallet/feebumper.h>
+#include <wallet/test/util.h>
+#include <wallet/test/wallet_test_fixture.h>
+
+#include <boost/test/unit_test.hpp>
+
+namespace wallet {
+namespace feebumper {
+BOOST_FIXTURE_TEST_SUITE(feebumper_tests, WalletTestingSetup)
+
+static void CheckMaxWeightComputation(const std::string& script_str, const std::vector<std::string>& witness_str_stack, const std::string& prevout_script_str, int64_t expected_max_weight)
+{
+    std::vector script_data(ParseHex(script_str));
+    CScript script(script_data.begin(), script_data.end());
+    CTxIn input(uint256(), 0, script);
+
+    for (const auto& s : witness_str_stack) {
+        input.scriptWitness.stack.push_back(ParseHex(s));
+    }
+
+    std::vector prevout_script_data(ParseHex(prevout_script_str));
+    CScript prevout_script(prevout_script_data.begin(), prevout_script_data.end());
+
+    int64_t weight = GetTransactionInputWeight(input);
+    SignatureWeights weights;
+    SignatureWeightChecker size_checker(weights, DUMMY_CHECKER);
+    bool script_ok = VerifyScript(input.scriptSig, prevout_script, &input.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, size_checker);
+    BOOST_CHECK(script_ok);
+    weight += weights.GetWeightDiffToMax();
+    BOOST_CHECK_EQUAL(weight, expected_max_weight);
+}
+
+BOOST_AUTO_TEST_CASE(external_max_weight_test)
+{
+    // P2PKH
+    CheckMaxWeightComputation("453042021f03c8957c5ce12940ee6e3333ecc3f633d9a1ac53a55b3ce0351c617fa96abe021f0dccdcce3ef45a63998be9ec748b561baf077b8e862941d0cd5ec08f5afe68012102fccfeb395f0ecd3a77e7bc31c3bc61dc987418b18e395d441057b42ca043f22c", {}, "76a914f60dcfd3392b28adc7662669603641f578eed72d88ac", 593);
+    // P2SH-P2WPKH
+    CheckMaxWeightComputation("160014001dca1b22c599b5a56a87c78417ad2ff39552f1", {"3042021f5443c58eaf45f3e5ef46f8516f966b334a7d497cedda4edb2b9fad57c90c3b021f63a77cb56cde848e2e2dd20b487eec2f53101f634193786083f60b4d23a82301", "026cfe86116f161057deb240201d6b82ebd4f161e0200d63dc9aca65a1d6b38bb7"}, "a9147c8ab5ad7708b97ccb6b483d57aba48ee85214df87", 364);
+    // P2WPKH
+    CheckMaxWeightComputation("", {"3042021f0f8906f0394979d5b737134773e5b88bf036c7d63542301d600ab677ba5a59021f0e9fe07e62c113045fa1c1532e2914720e8854d189c4f5b8c88f57956b704401", "0359edba11ed1a0568094a6296a16c4d5ee4c8cfe2f5e2e6826871b5ecf8188f79"}, "00149961a78658030cc824af4c54fbf5294bec0cabdd", 272);
+    // P2WSH HTLC
+    CheckMaxWeightComputation("", {"3042021f5c4c29e6b686aae5b6d0751e90208592ea96d26bc81d78b0d3871a94a21fa8021f74dc2f971e438ccece8699c8fd15704c41df219ab37b63264f2147d15c34d801", "01", "6321024cf55e52ec8af7866617dc4e7ff8433758e98799906d80e066c6f32033f685f967029000b275210214827893e2dcbe4ad6c20bd743288edad21100404eb7f52ccd6062fd0e7808f268ac"}, "002089e84892873c679b1129edea246e484fd914c2601f776d4f2f4a001eb8059703", 318);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+} // namespace feebumper
+} // namespace wallet