diff --git a/libsolutil/CommonData.cpp b/libsolutil/CommonData.cpp
index 437a090c2c28..0614abaf3090 100644
--- a/libsolutil/CommonData.cpp
+++ b/libsolutil/CommonData.cpp
@@ -29,7 +29,6 @@
 
 #include <boost/algorithm/string.hpp>
 
-using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 
@@ -41,7 +40,7 @@ static char const* lowerHexChars = "0123456789abcdef";
 
 }
 
-string solidity::util::toHex(uint8_t _data, HexCase _case)
+std::string solidity::util::toHex(uint8_t _data, HexCase _case)
 {
 	assertThrow(_case != HexCase::Mixed, BadHexCase, "Mixed case can only be used for byte arrays.");
 
@@ -53,7 +52,7 @@ string solidity::util::toHex(uint8_t _data, HexCase _case)
 	};
 }
 
-string solidity::util::toHex(bytes const& _data, HexPrefix _prefix, HexCase _case)
+std::string solidity::util::toHex(bytes const& _data, HexPrefix _prefix, HexCase _case)
 {
 	std::string ret(_data.size() * 2 + (_prefix == HexPrefix::Add ? 2 : 0), 0);
 
@@ -90,7 +89,7 @@ int solidity::util::fromHex(char _i, WhenError _throw)
 	if (_i >= 'A' && _i <= 'F')
 		return _i - 'A' + 10;
 	if (_throw == WhenError::Throw)
-		assertThrow(false, BadHexCharacter, to_string(_i));
+		assertThrow(false, BadHexCharacter, std::to_string(_i));
 	else
 		return -1;
 }
@@ -125,31 +124,31 @@ bytes solidity::util::fromHex(std::string const& _s, WhenError _throw)
 }
 
 
-bool solidity::util::passesAddressChecksum(string const& _str, bool _strict)
+bool solidity::util::passesAddressChecksum(std::string const& _str, bool _strict)
 {
-	string s = _str.substr(0, 2) == "0x" ? _str : "0x" + _str;
+	std::string s = _str.substr(0, 2) == "0x" ? _str : "0x" + _str;
 
 	if (s.length() != 42)
 		return false;
 
 	if (!_strict && (
-		s.find_first_of("abcdef") == string::npos ||
-		s.find_first_of("ABCDEF") == string::npos
+		s.find_first_of("abcdef") == std::string::npos ||
+		s.find_first_of("ABCDEF") == std::string::npos
 	))
 		return true;
 
 	return s == solidity::util::getChecksummedAddress(s);
 }
 
-string solidity::util::getChecksummedAddress(string const& _addr)
+std::string solidity::util::getChecksummedAddress(std::string const& _addr)
 {
-	string s = _addr.substr(0, 2) == "0x" ? _addr.substr(2) : _addr;
+	std::string s = _addr.substr(0, 2) == "0x" ? _addr.substr(2) : _addr;
 	assertThrow(s.length() == 40, InvalidAddress, "");
-	assertThrow(s.find_first_not_of("0123456789abcdefABCDEF") == string::npos, InvalidAddress, "");
+	assertThrow(s.find_first_not_of("0123456789abcdefABCDEF") == std::string::npos, InvalidAddress, "");
 
 	h256 hash = keccak256(boost::algorithm::to_lower_copy(s, std::locale::classic()));
 
-	string ret = "0x";
+	std::string ret = "0x";
 	for (unsigned i = 0; i < 40; ++i)
 	{
 		char addressCharacter = s[i];
@@ -162,16 +161,16 @@ string solidity::util::getChecksummedAddress(string const& _addr)
 	return ret;
 }
 
-bool solidity::util::isValidHex(string const& _string)
+bool solidity::util::isValidHex(std::string const& _string)
 {
 	if (_string.substr(0, 2) != "0x")
 		return false;
-	if (_string.find_first_not_of("0123456789abcdefABCDEF", 2) != string::npos)
+	if (_string.find_first_not_of("0123456789abcdefABCDEF", 2) != std::string::npos)
 		return false;
 	return true;
 }
 
-bool solidity::util::isValidDecimal(string const& _string)
+bool solidity::util::isValidDecimal(std::string const& _string)
 {
 	if (_string.empty())
 		return false;
@@ -180,14 +179,14 @@ bool solidity::util::isValidDecimal(string const& _string)
 	// No leading zeros
 	if (_string.front() == '0')
 		return false;
-	if (_string.find_first_not_of("0123456789") != string::npos)
+	if (_string.find_first_not_of("0123456789") != std::string::npos)
 		return false;
 	return true;
 }
 
-string solidity::util::formatAsStringOrNumber(string const& _value)
+std::string solidity::util::formatAsStringOrNumber(std::string const& _value)
 {
-	assertThrow(_value.length() <= 32, StringTooLong, "String to be formatted longer than 32 bytes.");
+	assertThrow(_value.length() <= 32, StringTooLong, "std::string to be formatted longer than 32 bytes.");
 
 	for (auto const& c: _value)
 		if (c <= 0x1f || c >= 0x7f || c == '"')
@@ -197,9 +196,9 @@ string solidity::util::formatAsStringOrNumber(string const& _value)
 }
 
 
-string solidity::util::escapeAndQuoteString(string const& _input)
+std::string solidity::util::escapeAndQuoteString(std::string const& _input)
 {
-	string out;
+	std::string out;
 
 	for (char c: _input)
 		if (c == '\\')
@@ -214,8 +213,8 @@ string solidity::util::escapeAndQuoteString(string const& _input)
 			out += "\\t";
 		else if (!isPrint(c))
 		{
-			ostringstream o;
-			o << "\\x" << std::hex << setfill('0') << setw(2) << (unsigned)(unsigned char)(c);
+			std::ostringstream o;
+			o << "\\x" << std::hex << std::setfill('0') << std::setw(2) << (unsigned)(unsigned char)(c);
 			out += o.str();
 		}
 		else
diff --git a/libsolutil/CommonIO.cpp b/libsolutil/CommonIO.cpp
index 6089f4db66c0..06ce23a02401 100644
--- a/libsolutil/CommonIO.cpp
+++ b/libsolutil/CommonIO.cpp
@@ -31,7 +31,6 @@
 #include <termios.h>
 #endif
 
-using namespace std;
 using namespace solidity::util;
 
 namespace
@@ -55,35 +54,35 @@ inline T readFile(boost::filesystem::path const& _file)
 
 	// get length of file:
 	is.seekg(0, is.end);
-	streamoff length = is.tellg();
+	std::streamoff length = is.tellg();
 	if (length == 0)
 		return ret; // do not read empty file (MSVC does not like it)
 	is.seekg(0, is.beg);
 
 	ret.resize((static_cast<size_t>(length) + c_elementSize - 1) / c_elementSize);
-	is.read(const_cast<char*>(reinterpret_cast<char const*>(ret.data())), static_cast<streamsize>(length));
+	is.read(const_cast<char*>(reinterpret_cast<char const*>(ret.data())), static_cast<std::streamsize>(length));
 	return ret;
 }
 
 }
 
-string solidity::util::readFileAsString(boost::filesystem::path const& _file)
+std::string solidity::util::readFileAsString(boost::filesystem::path const& _file)
 {
-	return readFile<string>(_file);
+	return readFile<std::string>(_file);
 }
 
-string solidity::util::readUntilEnd(istream& _stdin)
+std::string solidity::util::readUntilEnd(std::istream& _stdin)
 {
-	ostringstream ss;
+	std::ostringstream ss;
 	ss << _stdin.rdbuf();
 	return ss.str();
 }
 
-string solidity::util::readBytes(istream& _input, size_t _length)
+std::string solidity::util::readBytes(std::istream& _input, size_t _length)
 {
-	string output;
+	std::string output;
 	output.resize(_length);
-	_input.read(output.data(), static_cast<streamsize>(_length));
+	_input.read(output.data(), static_cast<std::streamsize>(_length));
 	// If read() reads fewer bytes it sets failbit in addition to eofbit.
 	if (_input.fail())
 		output.resize(static_cast<size_t>(_input.gcount()));
@@ -135,10 +134,10 @@ class DisableConsoleBuffering
 int solidity::util::readStandardInputChar()
 {
 	DisableConsoleBuffering disableConsoleBuffering;
-	return cin.get();
+	return std::cin.get();
 }
 
-string solidity::util::absolutePath(string const& _path, string const& _reference)
+std::string solidity::util::absolutePath(std::string const& _path, std::string const& _reference)
 {
 	boost::filesystem::path p(_path);
 	// Anything that does not start with `.` is an absolute path.
@@ -158,6 +157,6 @@ string solidity::util::absolutePath(string const& _path, string const& _referenc
 	return result.generic_string();
 }
 
-string solidity::util::sanitizePath(string const& _path) {
+std::string solidity::util::sanitizePath(std::string const& _path) {
 	return boost::filesystem::path(_path).generic_string();
 }
diff --git a/libsolutil/Exceptions.cpp b/libsolutil/Exceptions.cpp
index fa4021d3be7b..00fe3e26ce92 100644
--- a/libsolutil/Exceptions.cpp
+++ b/libsolutil/Exceptions.cpp
@@ -18,13 +18,12 @@
 
 #include <libsolutil/Exceptions.h>
 
-using namespace std;
 using namespace solidity::util;
 
 char const* Exception::what() const noexcept
 {
 	// Return the comment if available.
-	if (string const* cmt = comment())
+	if (std::string const* cmt = comment())
 		return cmt->data();
 
 	// Fallback to base what().
@@ -33,20 +32,20 @@ char const* Exception::what() const noexcept
 	return std::exception::what();
 }
 
-string Exception::lineInfo() const
+std::string Exception::lineInfo() const
 {
 	char const* const* file = boost::get_error_info<boost::throw_file>(*this);
 	int const* line = boost::get_error_info<boost::throw_line>(*this);
-	string ret;
+	std::string ret;
 	if (file)
 		ret += *file;
 	ret += ':';
 	if (line)
-		ret += to_string(*line);
+		ret += std::to_string(*line);
 	return ret;
 }
 
-string const* Exception::comment() const noexcept
+std::string const* Exception::comment() const noexcept
 {
 	return boost::get_error_info<errinfo_comment>(*this);
 }
diff --git a/libsolutil/IndentedWriter.cpp b/libsolutil/IndentedWriter.cpp
index 0e0aded3ccb2..b2a3c06c93c0 100644
--- a/libsolutil/IndentedWriter.cpp
+++ b/libsolutil/IndentedWriter.cpp
@@ -23,21 +23,20 @@
 #include <libsolutil/IndentedWriter.h>
 #include <libsolutil/Assertions.h>
 
-using namespace std;
 using namespace solidity::util;
 
-string IndentedWriter::format() const
+std::string IndentedWriter::format() const
 {
-	string result;
+	std::string result;
 	for (auto const& line: m_lines)
-		result += string(line.indentation * 4, ' ') + line.contents + "\n";
+		result += std::string(line.indentation * 4, ' ') + line.contents + "\n";
 	return result;
 }
 
 void IndentedWriter::newLine()
 {
 	if (!m_lines.back().contents.empty())
-		m_lines.emplace_back(Line{string(), m_lines.back().indentation});
+		m_lines.emplace_back(Line{std::string(), m_lines.back().indentation});
 }
 
 void IndentedWriter::indent()
@@ -53,12 +52,12 @@ void IndentedWriter::unindent()
 	m_lines.back().indentation--;
 }
 
-void IndentedWriter::add(string const& _str)
+void IndentedWriter::add(std::string const& _str)
 {
 	m_lines.back().contents += _str;
 }
 
-void IndentedWriter::addLine(string const& _line)
+void IndentedWriter::addLine(std::string const& _line)
 {
 	newLine();
 	add(_line);
diff --git a/libsolutil/IpfsHash.cpp b/libsolutil/IpfsHash.cpp
index dbf411dc783d..3599b7121830 100644
--- a/libsolutil/IpfsHash.cpp
+++ b/libsolutil/IpfsHash.cpp
@@ -23,7 +23,6 @@
 #include <libsolutil/CommonData.h>
 #include <libsolutil/Numeric.h>
 
-using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 
@@ -56,11 +55,11 @@ bytes encodeLinkData(bytes const& _data)
 	return bytes{0x12} + varintEncoding(_data.size()) + _data;
 }
 
-string base58Encode(bytes const& _data)
+std::string base58Encode(bytes const& _data)
 {
-	static string const alphabet{"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"};
+	static std::string const alphabet{"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"};
 	bigint data(util::toHex(_data, HexPrefix::Add));
-	string output;
+	std::string output;
 	while (data)
 	{
 		output += alphabet[static_cast<size_t>(data % alphabet.size())];
@@ -84,7 +83,7 @@ struct Chunk
 	size_t blockSize = 0;
 };
 
-using Chunks = vector<Chunk>;
+using Chunks = std::vector<Chunk>;
 
 Chunk combineLinks(Chunks& _links)
 {
@@ -153,7 +152,7 @@ bytes groupChunksBottomUp(Chunks _currentLevel)
 }
 }
 
-bytes solidity::util::ipfsHash(string _data)
+bytes solidity::util::ipfsHash(std::string _data)
 {
 	size_t const maxChunkSize = 1024 * 256;
 	size_t chunkCount = _data.length() / maxChunkSize + (_data.length() % maxChunkSize > 0 ? 1 : 0);
@@ -164,7 +163,7 @@ bytes solidity::util::ipfsHash(string _data)
 	for (size_t chunkIndex = 0; chunkIndex < chunkCount; chunkIndex++)
 	{
 		bytes chunkBytes = asBytes(
-			_data.substr(chunkIndex * maxChunkSize, min(maxChunkSize, _data.length() - chunkIndex * maxChunkSize))
+			_data.substr(chunkIndex * maxChunkSize, std::min(maxChunkSize, _data.length() - chunkIndex * maxChunkSize))
 		);
 
 		bytes lengthAsVarint = varintEncoding(chunkBytes.size());
@@ -197,7 +196,7 @@ bytes solidity::util::ipfsHash(string _data)
 	return groupChunksBottomUp(std::move(allChunks));
 }
 
-string solidity::util::ipfsHashBase58(string _data)
+std::string solidity::util::ipfsHashBase58(std::string _data)
 {
 	return base58Encode(ipfsHash(std::move(_data)));
 }
diff --git a/libsolutil/JSON.cpp b/libsolutil/JSON.cpp
index d27982acb364..27dcf677f299 100644
--- a/libsolutil/JSON.cpp
+++ b/libsolutil/JSON.cpp
@@ -30,8 +30,6 @@
 #include <map>
 #include <memory>
 
-using namespace std;
-
 static_assert(
 	(JSONCPP_VERSION_MAJOR == 1) && (JSONCPP_VERSION_MINOR == 9) && (JSONCPP_VERSION_PATCH == 3),
 	"Unexpected jsoncpp version: " JSONCPP_VERSION_STRING ". Expecting 1.9.3."
@@ -47,7 +45,7 @@ namespace
 class StreamWriterBuilder: public Json::StreamWriterBuilder
 {
 public:
-	explicit StreamWriterBuilder(map<string, Json::Value> const& _settings)
+	explicit StreamWriterBuilder(std::map<std::string, Json::Value> const& _settings)
 	{
 		for (auto const& iter: _settings)
 			this->settings_[iter.first] = iter.second;
@@ -68,10 +66,10 @@ class StrictModeCharReaderBuilder: public Json::CharReaderBuilder
 /// \param _input JSON input string
 /// \param _builder StreamWriterBuilder that is used to create new Json::StreamWriter
 /// \return serialized json object
-string print(Json::Value const& _input, Json::StreamWriterBuilder const& _builder)
+std::string print(Json::Value const& _input, Json::StreamWriterBuilder const& _builder)
 {
-	stringstream stream;
-	unique_ptr<Json::StreamWriter> writer(_builder.newStreamWriter());
+	std::stringstream stream;
+	std::unique_ptr<Json::StreamWriter> writer(_builder.newStreamWriter());
 	writer->write(_input, &stream);
 	return stream.str();
 }
@@ -82,9 +80,9 @@ string print(Json::Value const& _input, Json::StreamWriterBuilder const& _builde
 /// \param _json [out] resulting JSON object
 /// \param _errs [out] Formatted error messages
 /// \return \c true if the document was successfully parsed, \c false if an error occurred.
-bool parse(Json::CharReaderBuilder& _builder, string const& _input, Json::Value& _json, string* _errs)
+bool parse(Json::CharReaderBuilder& _builder, std::string const& _input, Json::Value& _json, std::string* _errs)
 {
-	unique_ptr<Json::CharReader> reader(_builder.newCharReader());
+	std::unique_ptr<Json::CharReader> reader(_builder.newCharReader());
 	return reader->parse(_input.c_str(), _input.c_str() + _input.length(), &_json, _errs);
 }
 
@@ -113,34 +111,34 @@ Json::Value removeNullMembers(Json::Value _json)
 	return _json;
 }
 
-string jsonPrettyPrint(Json::Value const& _input)
+std::string jsonPrettyPrint(Json::Value const& _input)
 {
 	return jsonPrint(_input, JsonFormat{ JsonFormat::Pretty });
 }
 
-string jsonCompactPrint(Json::Value const& _input)
+std::string jsonCompactPrint(Json::Value const& _input)
 {
 	return jsonPrint(_input, JsonFormat{ JsonFormat::Compact });
 }
 
-string jsonPrint(Json::Value const& _input, JsonFormat const& _format)
+std::string jsonPrint(Json::Value const& _input, JsonFormat const& _format)
 {
-	map<string, Json::Value> settings;
+	std::map<std::string, Json::Value> settings;
 	if (_format.format == JsonFormat::Pretty)
 	{
-		settings["indentation"] = string(_format.indent, ' ');
+		settings["indentation"] = std::string(_format.indent, ' ');
 		settings["enableYAMLCompatibility"] = true;
 	}
 	else
 		settings["indentation"] = "";
 	StreamWriterBuilder writerBuilder(settings);
-	string result = print(_input, writerBuilder);
+	std::string result = print(_input, writerBuilder);
 	if (_format.format == JsonFormat::Pretty)
 		boost::replace_all(result, " \n", "\n");
 	return result;
 }
 
-bool jsonParseStrict(string const& _input, Json::Value& _json, string* _errs /* = nullptr */)
+bool jsonParseStrict(std::string const& _input, Json::Value& _json, std::string* _errs /* = nullptr */)
 {
 	static StrictModeCharReaderBuilder readerBuilder;
 	return parse(readerBuilder, _input, _json, _errs);
diff --git a/libsolutil/Keccak256.cpp b/libsolutil/Keccak256.cpp
index 212804904974..c54dedabeb8f 100644
--- a/libsolutil/Keccak256.cpp
+++ b/libsolutil/Keccak256.cpp
@@ -25,8 +25,6 @@
 #include <cstdint>
 #include <cstring>
 
-using namespace std;
-
 namespace solidity::util
 {
 
diff --git a/libsolutil/StringUtils.cpp b/libsolutil/StringUtils.cpp
index d1c96fb2e227..de3a95668d32 100644
--- a/libsolutil/StringUtils.cpp
+++ b/libsolutil/StringUtils.cpp
@@ -19,18 +19,17 @@
  * @author Balajiganapathi S <balajiganapathi.s@gmail.com>
  * @date 2017
  *
- * String routines
+ * std::string routines
  */
 
 #include <libsolutil/StringUtils.h>
 #include <string>
 #include <vector>
 
-using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 
-bool solidity::util::stringWithinDistance(string const& _str1, string const& _str2, size_t _maxDistance, size_t _lenThreshold)
+bool solidity::util::stringWithinDistance(std::string const& _str1, std::string const& _str2, size_t _maxDistance, size_t _lenThreshold)
 {
 	if (_str1 == _str2)
 		return true;
@@ -47,13 +46,13 @@ bool solidity::util::stringWithinDistance(string const& _str1, string const& _st
 	return distance <= _maxDistance && distance < n1 && distance < n2;
 }
 
-size_t solidity::util::stringDistance(string const& _str1, string const& _str2)
+size_t solidity::util::stringDistance(std::string const& _str1, std::string const& _str2)
 {
 	size_t n1 = _str1.size();
 	size_t n2 = _str2.size();
 	// Optimize by storing only last 2 rows and current row. So first index is considered modulo 3
 	// This is a two-dimensional array of size 3 x (n2 + 1).
-	vector<size_t> dp(3 * (n2 + 1));
+	std::vector<size_t> dp(3 * (n2 + 1));
 
 	// In this dp formulation of Damerau–Levenshtein distance we are assuming that the strings are 1-based to make base case storage easier.
 	// So index accesser to _name1 and _name2 have to be adjusted accordingly
@@ -61,25 +60,25 @@ size_t solidity::util::stringDistance(string const& _str1, string const& _str2)
 		for (size_t i2 = 0; i2 <= n2; ++i2)
 		{
 			size_t x = 0;
-			if (min(i1, i2) == 0) // base case
-				x = max(i1, i2);
+			if (std::min(i1, i2) == 0) // base case
+				x = std::max(i1, i2);
 			else
 			{
 				size_t left = dp[(i1 - 1) % 3 + i2 * 3];
 				size_t up = dp[(i1 % 3) + (i2 - 1) * 3];
 				size_t upleft = dp[((i1 - 1) % 3) + (i2 - 1) * 3];
 				// deletion and insertion
-				x = min(left + 1, up + 1);
+				x = std::min(left + 1, up + 1);
 				if (_str1[i1-1] == _str2[i2-1])
 					// same chars, can skip
-					x = min(x, upleft);
+					x = std::min(x, upleft);
 				else
 					// different chars so try substitution
-					x = min(x, upleft + 1);
+					x = std::min(x, upleft + 1);
 
 				// transposing
 				if (i1 > 1 && i2 > 1 && _str1[i1 - 1] == _str2[i2 - 2] && _str1[i1 - 2] == _str2[i2 - 1])
-					x = min(x, dp[((i1 - 2) % 3) + (i2 - 2) * 3] + 1);
+					x = std::min(x, dp[((i1 - 2) % 3) + (i2 - 2) * 3] + 1);
 			}
 			dp[(i1 % 3) + i2 * 3] = x;
 		}
@@ -87,9 +86,9 @@ size_t solidity::util::stringDistance(string const& _str1, string const& _str2)
 	return dp[(n1 % 3) + n2 * 3];
 }
 
-string solidity::util::quotedAlternativesList(vector<string> const& suggestions)
+std::string solidity::util::quotedAlternativesList(std::vector<std::string> const& suggestions)
 {
-	vector<string> quotedSuggestions;
+	std::vector<std::string> quotedSuggestions;
 
 	for (auto& suggestion: suggestions)
 		quotedSuggestions.emplace_back("\"" + suggestion + "\"");
@@ -97,20 +96,20 @@ string solidity::util::quotedAlternativesList(vector<string> const& suggestions)
 	return joinHumanReadable(quotedSuggestions, ", ", " or ");
 }
 
-string solidity::util::suffixedVariableNameList(string const& _baseName, size_t _startSuffix, size_t _endSuffix)
+std::string solidity::util::suffixedVariableNameList(std::string const& _baseName, size_t _startSuffix, size_t _endSuffix)
 {
-	string result;
+	std::string result;
 	if (_startSuffix < _endSuffix)
 	{
-		result = _baseName + to_string(_startSuffix++);
+		result = _baseName + std::to_string(_startSuffix++);
 		while (_startSuffix < _endSuffix)
-			result += ", " + _baseName + to_string(_startSuffix++);
+			result += ", " + _baseName + std::to_string(_startSuffix++);
 	}
 	else if (_endSuffix < _startSuffix)
 	{
-		result = _baseName + to_string(_endSuffix++);
+		result = _baseName + std::to_string(_endSuffix++);
 		while (_endSuffix < _startSuffix)
-			result = _baseName + to_string(_endSuffix++) + ", " + result;
+			result = _baseName + std::to_string(_endSuffix++) + ", " + result;
 	}
 	return result;
 }
@@ -119,7 +118,7 @@ namespace
 {
 
 /// Try to format as N * 2**x
-optional<string> tryFormatPowerOfTwo(bigint const& _value)
+std::optional<std::string> tryFormatPowerOfTwo(bigint const& _value)
 {
 	bigint prefix = _value;
 
@@ -128,7 +127,7 @@ optional<string> tryFormatPowerOfTwo(bigint const& _value)
 	for (; (prefix & 0xff) == 0; prefix >>= 8)
 		++i;
 	if (i <= 2)
-		return nullopt;
+		return std::nullopt;
 
 	// 0x100 yields 2**8 (N is 1 and redundant)
 	if (prefix == 1)
@@ -150,11 +149,11 @@ optional<string> tryFormatPowerOfTwo(bigint const& _value)
 
 }
 
-string solidity::util::formatNumberReadable(bigint const& _value, bool _useTruncation)
+std::string solidity::util::formatNumberReadable(bigint const& _value, bool _useTruncation)
 {
 	bool const isNegative = _value < 0;
 	bigint const absValue = isNegative ? (bigint(-1) * _value) : bigint(_value);
-	string const sign = isNegative ? "-" : "";
+	std::string const sign = isNegative ? "-" : "";
 
 	// smaller numbers return as decimal
 	if (absValue <= 0x1000000)
@@ -165,7 +164,7 @@ string solidity::util::formatNumberReadable(bigint const& _value, bool _useTrunc
 	else if (auto result = tryFormatPowerOfTwo(absValue + 1))
 		return {sign + *result + (isNegative ? " + 1" : " - 1")};
 
-	string str = toHex(toCompactBigEndian(absValue), HexPrefix::Add, HexCase::Mixed);
+	std::string str = toHex(toCompactBigEndian(absValue), HexPrefix::Add, HexCase::Mixed);
 
 	if (_useTruncation)
 	{
diff --git a/libsolutil/SwarmHash.cpp b/libsolutil/SwarmHash.cpp
index 32e798d160d1..cf47cb15935b 100644
--- a/libsolutil/SwarmHash.cpp
+++ b/libsolutil/SwarmHash.cpp
@@ -22,7 +22,6 @@
 
 #include <libsolutil/Keccak256.h>
 
-using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 
@@ -42,7 +41,7 @@ h256 swarmHashSimple(bytesConstRef _data, size_t _size)
 	return keccak256(toLittleEndian(_size) + _data.toBytes());
 }
 
-h256 swarmHashIntermediate(string const& _input, size_t _offset, size_t _length)
+h256 swarmHashIntermediate(std::string const& _input, size_t _offset, size_t _length)
 {
 	bytesConstRef ref;
 	bytes innerNodes;
@@ -104,7 +103,7 @@ h256 chunkHash(bytesConstRef const _data, bool _forceHigherLevel = false)
 
 }
 
-h256 solidity::util::bzzr0Hash(string const& _input)
+h256 solidity::util::bzzr0Hash(std::string const& _input)
 {
 	return swarmHashIntermediate(_input, 0, _input.size());
 }
diff --git a/libsolutil/TemporaryDirectory.cpp b/libsolutil/TemporaryDirectory.cpp
index e82d87cf21ac..ff4504794156 100644
--- a/libsolutil/TemporaryDirectory.cpp
+++ b/libsolutil/TemporaryDirectory.cpp
@@ -26,7 +26,6 @@
 #include <regex>
 #include <iostream>
 
-using namespace std;
 using namespace solidity;
 using namespace solidity::util;
 
@@ -42,8 +41,8 @@ TemporaryDirectory::TemporaryDirectory(std::string const& _prefix):
 }
 
 TemporaryDirectory::TemporaryDirectory(
-	vector<boost::filesystem::path> const& _subdirectories,
-	string const& _prefix
+	std::vector<boost::filesystem::path> const& _subdirectories,
+	std::string const& _prefix
 ):
 	TemporaryDirectory(_prefix)
 {
@@ -71,9 +70,9 @@ TemporaryDirectory::~TemporaryDirectory()
 	uintmax_t numRemoved = fs::remove_all(m_path, errorCode);
 	if (errorCode.value() != boost::system::errc::success)
 	{
-		cerr << "Failed to completely remove temporary directory '" << m_path << "'. ";
-		cerr << "Only " << numRemoved << " files were actually removed." << endl;
-		cerr << "Reason: " << errorCode.message() << endl;
+		std::cerr << "Failed to completely remove temporary directory '" << m_path << "'. ";
+		std::cerr << "Only " << numRemoved << " files were actually removed." << std::endl;
+		std::cerr << "Reason: " << errorCode.message() << std::endl;
 	}
 }
 
diff --git a/libsolutil/Whiskers.cpp b/libsolutil/Whiskers.cpp
index b6d3ebde0cd6..1f026d9464a7 100644
--- a/libsolutil/Whiskers.cpp
+++ b/libsolutil/Whiskers.cpp
@@ -28,16 +28,15 @@
 
 #include <regex>
 
-using namespace std;
 using namespace solidity::util;
 
-Whiskers::Whiskers(string _template):
+Whiskers::Whiskers(std::string _template):
 	m_template(std::move(_template))
 {
 	checkTemplateValid();
 }
 
-Whiskers& Whiskers::operator()(string _parameter, string _value)
+Whiskers& Whiskers::operator()(std::string _parameter, std::string _value)
 {
 	checkParameterValid(_parameter);
 	checkParameterUnknown(_parameter);
@@ -46,7 +45,7 @@ Whiskers& Whiskers::operator()(string _parameter, string _value)
 	return *this;
 }
 
-Whiskers& Whiskers::operator()(string _parameter, bool _value)
+Whiskers& Whiskers::operator()(std::string _parameter, bool _value)
 {
 	checkParameterValid(_parameter);
 	checkParameterUnknown(_parameter);
@@ -56,8 +55,8 @@ Whiskers& Whiskers::operator()(string _parameter, bool _value)
 }
 
 Whiskers& Whiskers::operator()(
-	string _listParameter,
-	vector<map<string, string>> _values
+	std::string _listParameter,
+	std::vector<std::map<std::string, std::string>> _values
 )
 {
 	checkParameterValid(_listParameter);
@@ -70,15 +69,15 @@ Whiskers& Whiskers::operator()(
 	return *this;
 }
 
-string Whiskers::render() const
+std::string Whiskers::render() const
 {
 	return replace(m_template, m_parameters, m_conditions, m_listParameters);
 }
 
 void Whiskers::checkTemplateValid() const
 {
-	regex validTemplate("<[#?!\\/]\\+{0,1}[a-zA-Z0-9_$-]+(?:[^a-zA-Z0-9_$>-]|$)");
-	smatch match;
+	std::regex validTemplate("<[#?!\\/]\\+{0,1}[a-zA-Z0-9_$-]+(?:[^a-zA-Z0-9_$>-]|$)");
+	std::smatch match;
 	assertThrow(
 		!regex_search(m_template, match, validTemplate),
 		WhiskersError,
@@ -86,9 +85,9 @@ void Whiskers::checkTemplateValid() const
 	);
 }
 
-void Whiskers::checkParameterValid(string const& _parameter) const
+void Whiskers::checkParameterValid(std::string const& _parameter) const
 {
-	static regex validParam("^" + paramRegex() + "$");
+	static std::regex validParam("^" + paramRegex() + "$");
 	assertThrow(
 		regex_match(_parameter, validParam),
 		WhiskersError,
@@ -96,7 +95,7 @@ void Whiskers::checkParameterValid(string const& _parameter) const
 	);
 }
 
-void Whiskers::checkParameterUnknown(string const& _parameter) const
+void Whiskers::checkParameterUnknown(std::string const& _parameter) const
 {
 	assertThrow(
 		!m_parameters.count(_parameter),
@@ -115,13 +114,13 @@ void Whiskers::checkParameterUnknown(string const& _parameter) const
 	);
 }
 
-void Whiskers::checkTemplateContainsTags(string const& _parameter, vector<string> const& _prefixes) const
+void Whiskers::checkTemplateContainsTags(std::string const& _parameter, std::vector<std::string> const& _prefixes) const
 {
 	for (auto const& prefix: _prefixes)
 	{
-		string tag{"<" + prefix + _parameter + ">"};
+		std::string tag{"<" + prefix + _parameter + ">"};
 		assertThrow(
-			m_template.find(tag) != string::npos,
+			m_template.find(tag) != std::string::npos,
 			WhiskersError,
 			"Tag '" + tag + "' not found in template:\n" + m_template
 		);
@@ -131,17 +130,17 @@ void Whiskers::checkTemplateContainsTags(string const& _parameter, vector<string
 namespace
 {
 template<class ReplaceCallback>
-string regex_replace(
-	string const& _source,
-	regex const& _pattern,
+std::string regex_replace(
+	std::string const& _source,
+	std::regex const& _pattern,
 	ReplaceCallback _replace,
-	regex_constants::match_flag_type _flags = regex_constants::match_default
+	std::regex_constants::match_flag_type _flags = std::regex_constants::match_default
 )
 {
-	sregex_iterator curMatch(_source.begin(), _source.end(), _pattern, _flags);
-	sregex_iterator matchEnd;
-	string::const_iterator lastMatchedPos(_source.cbegin());
-	string result;
+	std::sregex_iterator curMatch(_source.begin(), _source.end(), _pattern, _flags);
+	std::sregex_iterator matchEnd;
+	std::string::const_iterator lastMatchedPos(_source.cbegin());
+	std::string result;
 	while (curMatch != matchEnd)
 	{
 		result.append(curMatch->prefix().first, curMatch->prefix().second);
@@ -154,23 +153,23 @@ string regex_replace(
 }
 }
 
-string Whiskers::replace(
-	string const& _template,
+std::string Whiskers::replace(
+	std::string const& _template,
 	StringMap const& _parameters,
-	map<string, bool> const& _conditions,
-	map<string, vector<StringMap>> const& _listParameters
+	std::map<std::string, bool> const& _conditions,
+	std::map<std::string, std::vector<StringMap>> const& _listParameters
 )
 {
-	static regex listOrTag(
+	static std::regex listOrTag(
 		"<(" + paramRegex() + ")>|"
 		"<#(" + paramRegex() + ")>((?:.|\\r|\\n)*?)</\\2>|"
 		"<\\?(\\+?" + paramRegex() + ")>((?:.|\\r|\\n)*?)(<!\\4>((?:.|\\r|\\n)*?))?</\\4>"
 	);
-	return regex_replace(_template, listOrTag, [&](match_results<string::const_iterator> _match) -> string
+	return regex_replace(_template, listOrTag, [&](std::match_results<std::string::const_iterator> _match) -> std::string
 	{
-		string tagName(_match[1]);
-		string listName(_match[2]);
-		string conditionName(_match[4]);
+		std::string tagName(_match[1]);
+		std::string listName(_match[2]);
+		std::string conditionName(_match[4]);
 		if (!tagName.empty())
 		{
 			assertThrow(
@@ -184,12 +183,12 @@ string Whiskers::replace(
 		}
 		else if (!listName.empty())
 		{
-			string templ(_match[3]);
+			std::string templ(_match[3]);
 			assertThrow(
 				_listParameters.count(listName),
 				WhiskersError, "List parameter " + listName + " not set."
 			);
-			string replacement;
+			std::string replacement;
 			for (auto const& parameters: _listParameters.at(listName))
 				replacement += replace(templ, joinMaps(_parameters, parameters), _conditions);
 			return replacement;
@@ -200,7 +199,7 @@ string Whiskers::replace(
 			bool conditionValue = false;
 			if (conditionName[0] == '+')
 			{
-				string tag = conditionName.substr(1);
+				std::string tag = conditionName.substr(1);
 
 				if (_parameters.count(tag))
 					conditionValue = !_parameters.at(tag).empty();
diff --git a/scripts/check_style.sh b/scripts/check_style.sh
index 7c1167490a58..5288cb9a5c6a 100755
--- a/scripts/check_style.sh
+++ b/scripts/check_style.sh
@@ -33,6 +33,7 @@ NAMESPACE_STD_FREE_FILES=(
     libsolidity/interface/*
     libsolidity/lsp/*
     libsolidity/parsing/*
+    libsolutil/*
 )
 
 (