diff --git a/src/bench/crypto_hash.cpp b/src/bench/crypto_hash.cpp
index bab22f598..5b0cf27e0 100644
--- a/src/bench/crypto_hash.cpp
+++ b/src/bench/crypto_hash.cpp
@@ -80,18 +80,16 @@ static void SipHash_32b(benchmark::State& state)
 static void FastRandom_32bit(benchmark::State& state)
 {
     FastRandomContext rng(true);
-    uint32_t x = 0;
     while (state.KeepRunning()) {
-        x += rng.rand32();
+        rng.rand32();
     }
 }
 
 static void FastRandom_1bit(benchmark::State& state)
 {
     FastRandomContext rng(true);
-    uint32_t x = 0;
     while (state.KeepRunning()) {
-        x += rng.randbool();
+        rng.randbool();
     }
 }
 
diff --git a/src/bench/rollingbloom.cpp b/src/bench/rollingbloom.cpp
index 43e763504..0a99ea318 100644
--- a/src/bench/rollingbloom.cpp
+++ b/src/bench/rollingbloom.cpp
@@ -12,7 +12,6 @@ static void RollingBloom(benchmark::State& state)
     CRollingBloomFilter filter(120000, 0.000001);
     std::vector<unsigned char> data(32);
     uint32_t count = 0;
-    uint64_t match = 0;
     while (state.KeepRunning()) {
         count++;
         data[0] = count;
@@ -25,7 +24,7 @@ static void RollingBloom(benchmark::State& state)
         data[1] = count >> 16;
         data[2] = count >> 8;
         data[3] = count;
-        match += filter.contains(data);
+        filter.contains(data);
     }
 }
 
diff --git a/src/test/descriptor_tests.cpp b/src/test/descriptor_tests.cpp
index f189222be..e739b84a4 100644
--- a/src/test/descriptor_tests.cpp
+++ b/src/test/descriptor_tests.cpp
@@ -64,7 +64,7 @@ void Check(const std::string& prv, const std::string& pub, int flags, const std:
     BOOST_CHECK_EQUAL(pub, pub2);
 
     // Check that both can be serialized with private key back to the private version, but not without private key.
-    std::string prv1, prv2;
+    std::string prv1;
     BOOST_CHECK(parse_priv->ToPrivateString(keys_priv, prv1));
     BOOST_CHECK_EQUAL(prv, prv1);
     BOOST_CHECK(!parse_priv->ToPrivateString(keys_pub, prv1));
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index bc671394c..67c377778 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -937,17 +937,19 @@ BOOST_AUTO_TEST_CASE(script_build)
         }
     }
 
+#ifdef UPDATE_JSON_TESTS
     std::string strGen;
-
+#endif
     for (TestBuilder& test : tests) {
         test.Test();
         std::string str = JSONPrettyPrint(test.GetJSON());
-#ifndef UPDATE_JSON_TESTS
+#ifdef UPDATE_JSON_TESTS
+        strGen += str + ",\n";
+#else
         if (tests_set.count(str) == 0) {
             BOOST_CHECK_MESSAGE(false, "Missing auto script_valid test: " + test.GetComment());
         }
 #endif
-        strGen += str + ",\n";
     }
 
 #ifdef UPDATE_JSON_TESTS
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 8bada4dce..c7ff7b547 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -640,8 +640,6 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
         innerUsage += memusage::DynamicUsage(links.parents) + memusage::DynamicUsage(links.children);
         bool fDependsWait = false;
         setEntries setParentCheck;
-        int64_t parentSizes = 0;
-        int64_t parentSigOpCost = 0;
         for (const CTxIn &txin : tx.vin) {
             // Check that every mempool transaction's inputs refer to available coins, or other mempool tx's.
             indexed_transaction_set::const_iterator it2 = mapTx.find(txin.prevout.hash);
@@ -649,10 +647,7 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
                 const CTransaction& tx2 = it2->GetTx();
                 assert(tx2.vout.size() > txin.prevout.n && !tx2.vout[txin.prevout.n].IsNull());
                 fDependsWait = true;
-                if (setParentCheck.insert(it2).second) {
-                    parentSizes += it2->GetTxSize();
-                    parentSigOpCost += it2->GetSigOpCost();
-                }
+                setParentCheck.insert(it2);
             } else {
                 assert(pcoins->HaveCoin(txin.prevout));
             }