diff --git a/src/policy/policy.h b/src/policy/policy.h
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -14,28 +14,45 @@
 class CCoinsViewCache;
 class CTransaction;
 
-/** Default for -blockmaxsize, which controls the maximum size of block the
- * mining code will create **/
+/**
+ * Default for -blockmaxsize, which controls the maximum size of block the
+ * mining code will create.
+ */
 static const uint64_t DEFAULT_MAX_GENERATED_BLOCK_SIZE = 2 * ONE_MEGABYTE;
-/** Default for -blockprioritypercentage, define the amount of block space
- * reserved to high priority transactions **/
+/**
+ * Default for -blockprioritypercentage, define the amount of block space
+ * reserved to high priority transactions.
+ */
 static const uint64_t DEFAULT_BLOCK_PRIORITY_PERCENTAGE = 5;
-/** Default for -blockmintxfee, which sets the minimum feerate for a transaction
- * in blocks created by mining code **/
+/**
+ * Default for -blockmintxfee, which sets the minimum feerate for a transaction
+ * in blocks created by mining code.
+ */
 static const Amount DEFAULT_BLOCK_MIN_TX_FEE(1000);
-/** The maximum size for transactions we're willing to relay/mine */
+/**
+ * The maximum size for transactions we're willing to relay/mine.
+ */
 static const unsigned int MAX_STANDARD_TX_SIZE = 100000;
-/** Maximum number of signature check operations in an IsStandard() P2SH script
+/**
+ * Maximum number of signature check operations in an IsStandard() P2SH script.
  */
 static const unsigned int MAX_P2SH_SIGOPS = 15;
-/** The maximum number of sigops we're willing to relay/mine in a single tx */
+/**
+ * The maximum number of sigops we're willing to relay/mine in a single tx.
+ */
 static const unsigned int MAX_STANDARD_TX_SIGOPS = MAX_TX_SIGOPS_COUNT / 5;
-/** Default for -maxmempool, maximum megabytes of mempool memory usage */
+/**
+ * Default for -maxmempool, maximum megabytes of mempool memory usage.
+ */
 static const unsigned int DEFAULT_MAX_MEMPOOL_SIZE = 300;
-/** Default for -incrementalrelayfee, which sets the minimum feerate increase
- * for mempool limiting or BIP 125 replacement **/
+/**
+ * Default for -incrementalrelayfee, which sets the minimum feerate increase for
+ * mempool limiting or BIP 125 replacement.
+ */
 static const CFeeRate MEMPOOL_FULL_FEE_INCREMENT(Amount(1000));
-/** Default for -bytespersigop */
+/**
+ * Default for -bytespersigop .
+ */
 static const unsigned int DEFAULT_BYTES_PER_SIGOP = 20;
 /**
  * Min feerate for defining dust. Historically this has been the same as the
@@ -51,20 +68,24 @@
  * with. However scripts violating these flags may still be present in valid
  * blocks and we must accept those blocks.
  */
-static const unsigned int STANDARD_SCRIPT_VERIFY_FLAGS =
+static const uint32_t STANDARD_SCRIPT_VERIFY_FLAGS =
     MANDATORY_SCRIPT_VERIFY_FLAGS | SCRIPT_VERIFY_DERSIG |
     SCRIPT_VERIFY_MINIMALDATA | SCRIPT_VERIFY_NULLDUMMY |
     SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS | SCRIPT_VERIFY_CLEANSTACK |
     SCRIPT_VERIFY_NULLFAIL | SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY |
     SCRIPT_VERIFY_CHECKSEQUENCEVERIFY | SCRIPT_VERIFY_LOW_S;
 
-/** For convenience, standard but not mandatory verify flags. */
-static const unsigned int STANDARD_NOT_MANDATORY_VERIFY_FLAGS =
+/**
+ * For convenience, standard but not mandatory verify flags.
+ */
+static const uint32_t STANDARD_NOT_MANDATORY_VERIFY_FLAGS =
     STANDARD_SCRIPT_VERIFY_FLAGS & ~MANDATORY_SCRIPT_VERIFY_FLAGS;
 
-/** Used as the flags parameter to sequence and nLocktime checks in
- * non-consensus code. */
-static const unsigned int STANDARD_LOCKTIME_VERIFY_FLAGS =
+/**
+ * Used as the flags parameter to sequence and nLocktime checks in non-consensus
+ * code.
+ */
+static const uint32_t STANDARD_LOCKTIME_VERIFY_FLAGS =
     LOCKTIME_VERIFY_SEQUENCE | LOCKTIME_MEDIAN_TIME_PAST;
 
 bool IsStandard(const CScript &scriptPubKey, txnouttype &whichType);
@@ -87,6 +108,6 @@
 
 extern CFeeRate incrementalRelayFee;
 extern CFeeRate dustRelayFee;
-extern unsigned int nBytesPerSigOp;
+extern uint32_t nBytesPerSigOp;
 
 #endif // BITCOIN_POLICY_POLICY_H
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -123,8 +123,8 @@
         return true;
     }
 
-    for (size_t i = 0; i < tx.vin.size(); i++) {
-        const CTxOut &prev = mapInputs.GetOutputFor(tx.vin[i]);
+    for (const CTxIn &in : tx.vin) {
+        const CTxOut &prev = mapInputs.GetOutputFor(in);
 
         std::vector<std::vector<uint8_t>> vSolutions;
         txnouttype whichType;
@@ -138,7 +138,7 @@
             std::vector<std::vector<uint8_t>> stack;
             // convert the scriptSig into a stack, so we can inspect the
             // redeemScript
-            if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE,
+            if (!EvalScript(stack, in.scriptSig, SCRIPT_VERIFY_NONE,
                             BaseSignatureChecker())) {
                 return false;
             }
@@ -157,4 +157,4 @@
 }
 
 CFeeRate dustRelayFee = CFeeRate(DUST_RELAY_TX_FEE);
-unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;
+uint32_t nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP;