diff --git a/src/amount.h b/src/amount.h
index 57df189cd..d380bcf33 100644
--- a/src/amount.h
+++ b/src/amount.h
@@ -1,224 +1,228 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_AMOUNT_H
 #define BITCOIN_AMOUNT_H
 
 #include "serialize.h"
 
 #include <cstdlib>
 #include <string>
 #include <type_traits>
 
+#ifdef __APPLE__
+#include <iostream>
+#endif
+
 struct Amount {
 private:
     int64_t amount;
 
 public:
     constexpr Amount() : amount(0) {}
 
     template <typename T>
     explicit constexpr Amount(T _camount) : amount(_camount) {
         static_assert(std::is_integral<T>(),
                       "Only integer types can be used as amounts");
     }
 
     constexpr Amount(const Amount &_camount) : amount(_camount.amount) {}
 
     // Allow access to underlying value for non-monetary operations
     int64_t GetSatoshis() const { return *this / Amount(1); }
 
     /**
      * Implement standard operators
      */
     Amount &operator+=(const Amount a) {
         amount += a.amount;
         return *this;
     }
     Amount &operator-=(const Amount a) {
         amount -= a.amount;
         return *this;
     }
 
     /**
      * Equality
      */
     friend constexpr bool operator==(const Amount a, const Amount b) {
         return a.amount == b.amount;
     }
     friend constexpr bool operator!=(const Amount a, const Amount b) {
         return !(a == b);
     }
 
     /**
      * Comparison
      */
     friend constexpr bool operator<(const Amount a, const Amount b) {
         return a.amount < b.amount;
     }
     friend constexpr bool operator>(const Amount a, const Amount b) {
         return b < a;
     }
     friend constexpr bool operator<=(const Amount a, const Amount b) {
         return !(a > b);
     }
     friend constexpr bool operator>=(const Amount a, const Amount b) {
         return !(a < b);
     }
 
     /**
      * Unary minus
      */
     constexpr Amount operator-() const { return Amount(-amount); }
 
     /**
      * Addition and subtraction.
      */
     friend constexpr Amount operator+(const Amount a, const Amount b) {
         return Amount(a.amount + b.amount);
     }
     friend constexpr Amount operator-(const Amount a, const Amount b) {
         return a + -b;
     }
 
     /**
      * Multiplication
      */
     friend constexpr Amount operator*(const int64_t a, const Amount b) {
         return Amount(a * b.amount);
     }
     friend constexpr Amount operator*(const int a, const Amount b) {
         return Amount(a * b.amount);
     }
 
     /**
      * Division
      */
     constexpr int64_t operator/(const Amount b) const {
         return amount / b.amount;
     }
     constexpr Amount operator/(const int64_t b) const {
         return Amount(amount / b);
     }
     constexpr Amount operator/(const int b) const { return Amount(amount / b); }
     Amount &operator/=(const int64_t n) {
         amount /= n;
         return *this;
     }
 
     /**
      * Modulus
      */
     constexpr int64_t operator%(const Amount b) const {
         return Amount(amount % b.amount) / Amount(1);
     }
     constexpr Amount operator%(const int64_t b) const {
         return Amount(amount % b);
     }
     constexpr Amount operator%(const int b) const { return Amount(amount % b); }
 
     /**
      * Do not implement double ops to get an error with double and ensure
      * casting to integer is explicit.
      */
     friend constexpr Amount operator*(const double a, const Amount b) = delete;
     constexpr Amount operator/(const double b) const = delete;
     constexpr Amount operator%(const double b) const = delete;
 
     // ostream support
     friend std::ostream &operator<<(std::ostream &stream, const Amount &ca) {
         return stream << ca.amount;
     }
 
     std::string ToString() const;
 
     // serialization support
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(amount);
     }
 };
 
 static const Amount SATOSHI(1);
 static const Amount CASH = 100 * SATOSHI;
 static const Amount COIN = 100000000 * SATOSHI;
 static const Amount CENT = COIN / 100;
 
 extern const std::string CURRENCY_UNIT;
 
 /**
  * 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 BCH for various reasons, but
  * rather a sanity check. As this sanity check is used by consensus-critical
  * 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 Amount MAX_MONEY = 21000000 * COIN;
 inline bool MoneyRange(const Amount nValue) {
     return (nValue >= Amount(0) && nValue <= MAX_MONEY);
 }
 
 /**
  * Fee rate in satoshis per kilobyte: Amount / kB
  */
 class CFeeRate {
 private:
     // unit is satoshis-per-1,000-bytes
     Amount nSatoshisPerK;
 
 public:
     /** Fee rate of 0 satoshis per kB */
     CFeeRate() : nSatoshisPerK(0) {}
     explicit CFeeRate(const Amount _nSatoshisPerK)
         : nSatoshisPerK(_nSatoshisPerK) {}
     /**
      * Constructor for a fee rate in satoshis per kB. The size in bytes must not
      * exceed (2^63 - 1)
      */
     CFeeRate(const Amount nFeePaid, size_t nBytes);
     CFeeRate(const CFeeRate &other) { nSatoshisPerK = other.nSatoshisPerK; }
     /**
      * Return the fee in satoshis for the given size in bytes.
      */
     Amount GetFee(size_t nBytes) const;
     /**
      * Return the fee in satoshis for a size of 1000 bytes
      */
     Amount 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;
     }
     std::string ToString() const;
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(nSatoshisPerK);
     }
 };
 
 #endif //  BITCOIN_AMOUNT_H