diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -460,14 +460,14 @@
     // It's not possible to get reasonable estimates for confTarget of 1
     if (confTarget <= 1 ||
         (unsigned int)confTarget > feeStats.GetMaxConfirms()) {
-        return CFeeRate(0);
+        return CFeeRate(Amount(0));
     }
 
     double median = feeStats.EstimateMedianVal(
         confTarget, SUFFICIENT_FEETXS, MIN_SUCCESS_PCT, true, nBestSeenHeight);
 
     if (median < 0) {
-        return CFeeRate(0);
+        return CFeeRate(Amount(0));
     }
 
     return CFeeRate(Amount(int64_t(median)));
@@ -482,7 +482,7 @@
     // Return failure if trying to analyze a target we're not tracking
     if (confTarget <= 0 ||
         (unsigned int)confTarget > feeStats.GetMaxConfirms()) {
-        return CFeeRate(0);
+        return CFeeRate(Amount(0));
     }
 
     // It's not possible to get reasonable estimates for confTarget of 1
@@ -508,12 +508,12 @@
         pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                        1000000)
             .GetFeePerK();
-    if (minPoolFee > 0 && minPoolFee > int64_t(median)) {
+    if (minPoolFee > Amount(0) && minPoolFee > Amount(int64_t(median))) {
         return CFeeRate(minPoolFee);
     }
 
     if (median < 0) {
-        return CFeeRate(0);
+        return CFeeRate(Amount(0));
     }
 
     return CFeeRate(Amount(int64_t(median)));
@@ -535,7 +535,7 @@
         pool.GetMinFee(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                        1000000)
             .GetFeePerK();
-    if (minPoolFee > 0) {
+    if (minPoolFee > Amount(0)) {
         return double(INF_PRIORITY.GetSatoshis());
     }
 
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -141,11 +141,11 @@
     }
 
     void SetNull() {
-        nValue = -1;
+        nValue = Amount(-1);
         scriptPubKey.clear();
     }
 
-    bool IsNull() const { return (nValue == -1); }
+    bool IsNull() const { return (nValue == Amount(-1)); }
 
     Amount GetDustThreshold(const CFeeRate &minRelayTxFee) const {
         // "Dust" is defined in terms of CTransaction::minRelayTxFee, which has
@@ -157,7 +157,7 @@
         // txout is 31 bytes big, and will need a CTxIn of at least 67 bytes to
         // spend: so dust is a spendable txout less than 294*minRelayTxFee/1000
         // (in satoshis).
-        if (scriptPubKey.IsUnspendable()) return 0;
+        if (scriptPubKey.IsUnspendable()) return Amount(0);
 
         size_t nSize = GetSerializeSize(*this, SER_DISK, 0);
 
diff --git a/src/primitives/transaction.cpp b/src/primitives/transaction.cpp
--- a/src/primitives/transaction.cpp
+++ b/src/primitives/transaction.cpp
@@ -85,7 +85,7 @@
       nLockTime(tx.nLockTime), hash(ComputeHash()) {}
 
 Amount CTransaction::GetValueOut() const {
-    Amount nValueOut = 0;
+    Amount nValueOut(0);
     for (std::vector<CTxOut>::const_iterator it(vout.begin()); it != vout.end();
          ++it) {
         nValueOut += it->nValue;
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -203,8 +203,8 @@
     assert(txin.prevout.n < txFrom.vout.size());
     const CTxOut &txout = txFrom.vout[txin.prevout.n];
 
-    return SignSignature(keystore, txout.scriptPubKey, txTo, nIn,
-                         txout.nValue.GetSatoshis(), nHashType);
+    return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, txout.nValue,
+                         nHashType);
 }
 
 static std::vector<valtype> CombineMultisig(