diff --git a/src/amount.h b/src/amount.h
--- a/src/amount.h
+++ b/src/amount.h
@@ -8,7 +8,7 @@
 
 #include "serialize.h"
 
-#include <stdlib.h>
+#include <cstdlib>
 #include <string>
 
 /** Amount in satoshis (Can be negative) */
@@ -19,7 +19,8 @@
 
 extern const std::string CURRENCY_UNIT;
 
-/** No amount larger than this (in satoshi) is valid.
+/**
+ * No amount larger than this (in satoshi) is valid.
  *
  * Note that this constant is *not* the total money supply, which in Bitcoin
  * currently happens to be less than 21,000,000 BTC for various reasons, but
@@ -27,24 +28,31 @@
  * validation code, the exact value of the MAX_MONEY constant is consensus
  * critical; in unusual circumstances like a(nother) overflow bug that allowed
  * for the creation of coins out of thin air modification could lead to a fork.
- * */
+ */
 static const CAmount MAX_MONEY = 21000000 * COIN;
-inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
+inline bool MoneyRange(const CAmount &nValue) {
+    return (nValue >= 0 && nValue <= MAX_MONEY);
+}
 
 /**
  * Fee rate in satoshis per kilobyte: CAmount / kB
  */
-class CFeeRate
-{
+class CFeeRate {
 private:
-    CAmount nSatoshisPerK; // unit is satoshis-per-1,000-bytes
+    // unit is satoshis-per-1,000-bytes
+    CAmount nSatoshisPerK;
+
 public:
     /** Fee rate of 0 satoshis per kB */
-    CFeeRate() : nSatoshisPerK(0) { }
-    explicit CFeeRate(const CAmount& _nSatoshisPerK): nSatoshisPerK(_nSatoshisPerK) { }
-    /** Constructor for a fee rate in satoshis per kB. The size in bytes must not exceed (2^63 - 1)*/
-    CFeeRate(const CAmount& nFeePaid, size_t nBytes);
-    CFeeRate(const CFeeRate& other) { nSatoshisPerK = other.nSatoshisPerK; }
+    CFeeRate() : nSatoshisPerK(0) {}
+    explicit CFeeRate(const CAmount &_nSatoshisPerK)
+        : nSatoshisPerK(_nSatoshisPerK) {}
+    /**
+     * Constructor for a fee rate in satoshis per kB. The size in bytes must not
+     * exceed (2^63 - 1)
+     */
+    CFeeRate(const CAmount &nFeePaid, size_t nBytes);
+    CFeeRate(const CFeeRate &other) { nSatoshisPerK = other.nSatoshisPerK; }
     /**
      * Return the fee in satoshis for the given size in bytes.
      */
@@ -53,18 +61,31 @@
      * Return the fee in satoshis for a size of 1000 bytes
      */
     CAmount GetFeePerK() const { return GetFee(1000); }
-    friend bool operator<(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK < b.nSatoshisPerK; }
-    friend bool operator>(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK > b.nSatoshisPerK; }
-    friend bool operator==(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK == b.nSatoshisPerK; }
-    friend bool operator<=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK <= b.nSatoshisPerK; }
-    friend bool operator>=(const CFeeRate& a, const CFeeRate& b) { return a.nSatoshisPerK >= b.nSatoshisPerK; }
-    CFeeRate& operator+=(const CFeeRate& a) { nSatoshisPerK += a.nSatoshisPerK; return *this; }
+    friend bool operator<(const CFeeRate &a, const CFeeRate &b) {
+        return a.nSatoshisPerK < b.nSatoshisPerK;
+    }
+    friend bool operator>(const CFeeRate &a, const CFeeRate &b) {
+        return a.nSatoshisPerK > b.nSatoshisPerK;
+    }
+    friend bool operator==(const CFeeRate &a, const CFeeRate &b) {
+        return a.nSatoshisPerK == b.nSatoshisPerK;
+    }
+    friend bool operator<=(const CFeeRate &a, const CFeeRate &b) {
+        return a.nSatoshisPerK <= b.nSatoshisPerK;
+    }
+    friend bool operator>=(const CFeeRate &a, const CFeeRate &b) {
+        return a.nSatoshisPerK >= b.nSatoshisPerK;
+    }
+    CFeeRate &operator+=(const CFeeRate &a) {
+        nSatoshisPerK += a.nSatoshisPerK;
+        return *this;
+    }
     std::string ToString() const;
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action) {
+    inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(nSatoshisPerK);
     }
 };
diff --git a/src/amount.cpp b/src/amount.cpp
--- a/src/amount.cpp
+++ b/src/amount.cpp
@@ -9,8 +9,7 @@
 
 const std::string CURRENCY_UNIT = "BTC";
 
-CFeeRate::CFeeRate(const CAmount& nFeePaid, size_t nBytes_)
-{
+CFeeRate::CFeeRate(const CAmount &nFeePaid, size_t nBytes_) {
     assert(nBytes_ <= uint64_t(std::numeric_limits<int64_t>::max()));
     int64_t nSize = int64_t(nBytes_);
 
@@ -20,24 +19,21 @@
         nSatoshisPerK = 0;
 }
 
-CAmount CFeeRate::GetFee(size_t nBytes_) const
-{
+CAmount CFeeRate::GetFee(size_t nBytes_) const {
     assert(nBytes_ <= uint64_t(std::numeric_limits<int64_t>::max()));
     int64_t nSize = int64_t(nBytes_);
 
     CAmount nFee = nSatoshisPerK * nSize / 1000;
 
     if (nFee == 0 && nSize != 0) {
-        if (nSatoshisPerK > 0)
-            nFee = CAmount(1);
-        if (nSatoshisPerK < 0)
-            nFee = CAmount(-1);
+        if (nSatoshisPerK > 0) nFee = CAmount(1);
+        if (nSatoshisPerK < 0) nFee = CAmount(-1);
     }
 
     return nFee;
 }
 
-std::string CFeeRate::ToString() const
-{
-    return strprintf("%d.%08d %s/kB", nSatoshisPerK / COIN, nSatoshisPerK % COIN, CURRENCY_UNIT);
+std::string CFeeRate::ToString() const {
+    return strprintf("%d.%08d %s/kB", nSatoshisPerK / COIN,
+                     nSatoshisPerK % COIN, CURRENCY_UNIT);
 }