diff --git a/libsolidity/lsp/LanguageServer.cpp b/libsolidity/lsp/LanguageServer.cpp
index f704eafee..7e38a37d7 100644
--- a/libsolidity/lsp/LanguageServer.cpp
+++ b/libsolidity/lsp/LanguageServer.cpp
@@ -189,11 +189,11 @@ void LanguageServer::changeConfiguration(Json::Value const& _settings)
 	if (auto traceLogFileNode = _settings["trace-log-file"])
 	{
 		if (traceLogFileNode.isString())
-			m_client.setTraceLogFile(boost::filesystem::path(_settings["trace-log-file"].asString()));
-		if (traceLogFileNode.isNull())
+			m_client.setTraceLogFile(boost::filesystem::path(traceLogFileNode.asString()));
+		else if (traceLogFileNode.isNull())
 			m_client.setTraceLogFile(nullopt);
 		else
-			lspAssert(false, ErrorCode::InvalidParams, "Invalid trace-log-file value. Must be a path to a file.");
+			lspAssert(false, ErrorCode::InvalidParams, "Invalid trace-log-file value. Must be a path to a file. "s + std::to_string(traceLogFileNode.type()));
 	}
 
 	m_settingsObject = _settings;
diff --git a/libsolidity/lsp/Transport.cpp b/libsolidity/lsp/Transport.cpp
index 608127d55..3cabec0f5 100644
--- a/libsolidity/lsp/Transport.cpp
+++ b/libsolidity/lsp/Transport.cpp
@@ -42,6 +42,12 @@ using namespace std;
 using namespace solidity::lsp;
 
 // {{{ Transport
+ofstream Transport::traceLogFileStream() const
+{
+	lspAssert(m_traceLogFilePath, ErrorCode::InternalError, "");
+	return ofstream(m_traceLogFilePath.value().generic_string(), ios::app);
+}
+
 optional<Json::Value> Transport::receive()
 {
 	auto const headers = parseHeaders();
@@ -59,21 +65,21 @@ optional<Json::Value> Transport::receive()
 
 	string const data = readBytes(stoul(headers->at("content-length")));
 
-	if (m_traceLogFilePath)
-	{
-		ofstream traceLogger(m_traceLogFilePath.value().generic_string(), ios::app);
-		traceLogger << "Received: " << data << endl;
-	}
-
 	Json::Value jsonMessage;
 	string jsonParsingErrors;
 	solidity::util::jsonParseStrict(data, jsonMessage, &jsonParsingErrors);
 	if (!jsonParsingErrors.empty() || !jsonMessage || !jsonMessage.isObject())
 	{
+		if (m_traceLogFilePath)
+			traceLogFileStream() << "{\"Received\": " << util::jsonPrettyPrint(jsonMessage) << "}," << endl;
+
 		error({}, ErrorCode::ParseError, "Could not parse RPC JSON payload. " + jsonParsingErrors);
 		return nullopt;
 	}
 
+	if (m_traceLogFilePath)
+		traceLogFileStream() << "{\"Received\": " << util::jsonPrettyPrint(jsonMessage) << "}," << endl;
+
 	return {std::move(jsonMessage)};
 }
 
@@ -150,10 +156,7 @@ void Transport::send(Json::Value _json, MessageID _id)
 	string const jsonString = solidity::util::jsonCompactPrint(_json);
 
 	if (m_traceLogFilePath)
-	{
-		ofstream traceLogger(m_traceLogFilePath.value().generic_string(), ios::app);
-		traceLogger << "Sending: " << jsonString << endl;
-	}
+		traceLogFileStream() << "{\"Sending\": " << jsonString << "}," << endl;
 
 	writeBytes(fmt::format("Content-Length: {}\r\n\r\n", jsonString.size()));
 	writeBytes(jsonString);
diff --git a/libsolidity/lsp/Transport.h b/libsolidity/lsp/Transport.h
index d1df026ed..86ba74c75 100644
--- a/libsolidity/lsp/Transport.h
+++ b/libsolidity/lsp/Transport.h
@@ -109,6 +109,8 @@ public:
 	/// to be written to if trace value is set to verbose.
 	void setTraceLogFile(std::optional<boost::filesystem::path> _pathToLogfile);
 
+	std::ofstream traceLogFileStream() const;
+
 private:
 	TraceValue m_logTrace = TraceValue::Off;
 	std::optional<boost::filesystem::path> m_traceLogFilePath;
diff --git a/solc/CommandLineInterface.cpp b/solc/CommandLineInterface.cpp
index e215405a1..3a12e0790 100644
--- a/solc/CommandLineInterface.cpp
+++ b/solc/CommandLineInterface.cpp
@@ -913,6 +913,8 @@ void CommandLineInterface::handleAst()
 void CommandLineInterface::serveLSP()
 {
 	lsp::StdioTransport transport;
+	transport.setTraceLogFile(m_options.languageServer.traceLogFile);
+
 	if (!lsp::LanguageServer{transport}.run())
 		solThrow(CommandLineExecutionError, "LSP terminated abnormally.");
 }
diff --git a/solc/CommandLineParser.cpp b/solc/CommandLineParser.cpp
index 2c765d0e3..f7e89b13c 100644
--- a/solc/CommandLineParser.cpp
+++ b/solc/CommandLineParser.cpp
@@ -61,6 +61,7 @@ static string const g_strLicense = "license";
 static string const g_strLibraries = "libraries";
 static string const g_strLink = "link";
 static string const g_strLSP = "lsp";
+static string const g_strLSPTrace = "lsp-trace";
 static string const g_strMachine = "machine";
 static string const g_strMetadataHash = "metadata-hash";
 static string const g_strMetadataLiteral = "metadata-literal";
@@ -649,6 +650,16 @@ General Information)").c_str(),
 	;
 	desc.add(alternativeInputModes);
 
+	po::options_description lspModeOptions("LSP Mode Options");
+	lspModeOptions.add_options()
+		(
+			g_strLSPTrace.c_str(),
+			po::value<string>()->value_name(""),
+			"Enables trace I/O logging to a given file."
+		)
+	;
+	desc.add(lspModeOptions);
+
 	po::options_description assemblyModeOptions("Assembly Mode Options");
 	assemblyModeOptions.add_options()
 		(
@@ -942,7 +953,12 @@ void CommandLineParser::processArgs()
 		);
 
 	if (m_options.input.mode == InputMode::LanguageServer)
+	{
+		if (m_args.count("lsp-trace"))
+			m_options.languageServer.traceLogFile = boost::filesystem::path(m_args.at("lsp-trace").as<string>());
+
 		return;
+	}
 
 	checkMutuallyExclusive({g_strColor, g_strNoColor});
 
diff --git a/solc/CommandLineParser.h b/solc/CommandLineParser.h
index 108a16cd2..50ba66e52 100644
--- a/solc/CommandLineParser.h
+++ b/solc/CommandLineParser.h
@@ -227,6 +227,11 @@ struct CommandLineOptions
 		std::optional<std::string> yulSteps;
 	} optimizer;
 
+	struct
+	{
+		std::optional<boost::filesystem::path> traceLogFile = std::nullopt;
+	} languageServer;
+
 	struct
 	{
 		bool initialize = false;