diff --git a/mix/ClientModel.cpp b/mix/ClientModel.cpp
index 4b4eb70d1..6b5242084 100644
--- a/mix/ClientModel.cpp
+++ b/mix/ClientModel.cpp
@@ -387,14 +387,11 @@ void ClientModel::executeSequence(vector<TransactionSettings> const& _sequence,
 
 std::pair<QString, int> ClientModel::resolvePair(QString const& _contractId)
 {
-	 std::pair<QString, int> ret;
-	 ret.first = _contractId;
-	 ret.second = 0;
+	 std::pair<QString, int> ret = std::make_pair(_contractId, 0);
 	 if (_contractId.startsWith("<") && _contractId.endsWith(">"))
 	 {
 		 QStringList values = ret.first.remove("<").remove(">").split(" - ");
-		 ret.first = values[0];
-		 ret.second = values[1].toUInt();
+		 ret = std::make_pair(values[0], values[1].toUInt());
 	 }
 	 return ret;
 }
diff --git a/mix/CodeModel.cpp b/mix/CodeModel.cpp
index 81f01a556..424732c2b 100644
--- a/mix/CodeModel.cpp
+++ b/mix/CodeModel.cpp
@@ -360,7 +360,7 @@ void CodeModel::gasEstimation(solidity::CompilerStack const& _cs)
 {
 	if (m_gasCostsMaps)
 		m_gasCostsMaps->deleteLater();
-	m_gasCostsMaps = new GasMapWrapper();
+	m_gasCostsMaps = new GasMapWrapper;
 	for (std::string n: _cs.getContractNames())
 	{
 		ContractDefinition const& contractDefinition = _cs.getContractDefinition(n);
diff --git a/mix/CodeModel.h b/mix/CodeModel.h
index 75e350c58..dcf3d0c1e 100644
--- a/mix/CodeModel.h
+++ b/mix/CodeModel.h
@@ -137,7 +137,7 @@ class GasMapWrapper: public QObject
 	Q_PROPERTY(GasCostsMaps gasMaps MEMBER m_gasMaps CONSTANT)
 
 public:
-	GasMapWrapper(QObject* _parent = 0): QObject(_parent){}
+	GasMapWrapper(QObject* _parent = nullptr): QObject(_parent){}
 	void push(QString _source, int _start, int _end, QString _value, bool _isInfinite);
 	bool contains(QString _key);
 	void insert(QString _source, QVariantList _variantList);