diff --git a/test/CommonSyntaxTest.cpp b/test/CommonSyntaxTest.cpp
index 79b597804..b3c242957 100644
--- a/test/CommonSyntaxTest.cpp
+++ b/test/CommonSyntaxTest.cpp
@@ -114,7 +114,7 @@ void CommonSyntaxTest::printSource(ostream& _stream, string const& _linePrefix,
 				{
 					assert(static_cast<size_t>(error.locationStart) <= source.length());
 					assert(static_cast<size_t>(error.locationEnd) <= source.length());
-					bool isWarning = error.type == "Warning";
+					bool isWarning = (error.type == Error::Type::Warning);
 					for (int i = error.locationStart; i < error.locationEnd; i++)
 						if (isWarning)
 						{
@@ -192,8 +192,8 @@ void CommonSyntaxTest::printErrorList(
 		for (auto const& error: _errorList)
 		{
 			{
-				util::AnsiColorized scope(_stream, _formatted, {BOLD, (error.type == "Warning") ? YELLOW : RED});
-				_stream << _linePrefix << error.type;
+				util::AnsiColorized scope(_stream, _formatted, {BOLD, (error.type == Error::Type::Warning) ? YELLOW : RED});
+				_stream << _linePrefix << Error::formatErrorType(error.type);
 				if (error.errorId.has_value())
 					_stream << ' ' << error.errorId->error;
 				_stream << ": ";
@@ -246,7 +246,11 @@ vector<SyntaxTestError> CommonSyntaxTest::parseExpectations(istream& _stream)
 		auto typeBegin = it;
 		while (it != line.end() && isalpha(*it, locale::classic()))
 			++it;
-		string errorType(typeBegin, it);
+
+		std::string errorTypeStr(typeBegin, it);
+		optional<Error::Type> errorType = Error::parseErrorType(errorTypeStr);
+		if (!errorType.has_value())
+			BOOST_THROW_EXCEPTION(runtime_error("Invalid error type: " + errorTypeStr));
 
 		skipWhitespace(it, line.end());
 
@@ -283,7 +287,7 @@ vector<SyntaxTestError> CommonSyntaxTest::parseExpectations(istream& _stream)
 
 		string errorMessage(it, line.end());
 		expectations.emplace_back(SyntaxTestError{
-			std::move(errorType),
+			errorType.value(),
 			std::move(errorId),
 			std::move(errorMessage),
 			std::move(sourceName),
diff --git a/test/CommonSyntaxTest.h b/test/CommonSyntaxTest.h
index 606f61a88..fb46c37a6 100644
--- a/test/CommonSyntaxTest.h
+++ b/test/CommonSyntaxTest.h
@@ -34,7 +34,7 @@ namespace solidity::test
 
 struct SyntaxTestError
 {
-	std::string type;
+	langutil::Error::Type type;
 	std::optional<langutil::ErrorId> errorId;
 	std::string message;
 	std::string sourceName;
diff --git a/test/libsolidity/SyntaxTest.cpp b/test/libsolidity/SyntaxTest.cpp
index 906391e01..90003768e 100644
--- a/test/libsolidity/SyntaxTest.cpp
+++ b/test/libsolidity/SyntaxTest.cpp
@@ -86,7 +86,7 @@ void SyntaxTest::parseAndAnalyze()
 	catch (UnimplementedFeatureError const& _e)
 	{
 		m_errorList.emplace_back(SyntaxTestError{
-			"UnimplementedFeatureError",
+			Error::Type::UnimplementedFeatureError,
 			nullopt,
 			errorMessage(_e),
 			"",
@@ -135,7 +135,7 @@ void SyntaxTest::filterObtainedErrors()
 			}
 		}
 		m_errorList.emplace_back(SyntaxTestError{
-			Error::formatErrorType(currentError->type()),
+			currentError->type(),
 			currentError->errorId(),
 			errorMessage(*currentError),
 			sourceName,
diff --git a/test/libyul/SyntaxTest.cpp b/test/libyul/SyntaxTest.cpp
index cea1d5745..20aadcf19 100644
--- a/test/libyul/SyntaxTest.cpp
+++ b/test/libyul/SyntaxTest.cpp
@@ -61,7 +61,7 @@ void SyntaxTest::parseAndAnalyze()
 		}
 
 		m_errorList.emplace_back(SyntaxTestError{
-			Error::formatErrorType(error->type()),
+			error->type(),
 			error->errorId(),
 			errorMessage(*error),
 			name,