diff --git a/src/emitter.cpp b/src/emitter.cpp
index 08b8fdd..6924bea 100644
--- a/src/emitter.cpp
+++ b/src/emitter.cpp
@@ -702,7 +702,7 @@ void Emitter::StartedScalar() { m_pState->StartedScalar(); }
 // *******************************************************************************************
 // overloads of Write
 
-StringEscaping::value GetStringEscapingStyle(const EMITTER_MANIP emitterManip) {
+StringEscaping GetStringEscapingStyle(const EMITTER_MANIP emitterManip) {
   switch (emitterManip) {
     case EscapeNonAscii:
       return StringEscaping::NonAscii;
@@ -718,9 +718,9 @@ Emitter& Emitter::Write(const std::string& str) {
   if (!good())
     return *this;
 
-  StringEscaping::value stringEscaping = GetStringEscapingStyle(m_pState->GetOutputCharset());
+  StringEscaping stringEscaping = GetStringEscapingStyle(m_pState->GetOutputCharset());
 
-  const StringFormat::value strFormat =
+  const StringFormat strFormat =
       Utils::ComputeStringFormat(str, m_pState->GetStringFormat(),
                                  m_pState->CurGroupFlowType(), stringEscaping == StringEscaping::NonAscii);
 
diff --git a/src/emitterutils.cpp b/src/emitterutils.cpp
index adb0560..cbe5d22 100644
--- a/src/emitterutils.cpp
+++ b/src/emitterutils.cpp
@@ -227,7 +227,7 @@ std::pair<uint16_t, uint16_t> EncodeUTF16SurrogatePair(int codePoint) {
   };
 }
 
-void WriteDoubleQuoteEscapeSequence(ostream_wrapper& out, int codePoint, StringEscaping::value stringEscapingStyle) {
+void WriteDoubleQuoteEscapeSequence(ostream_wrapper& out, int codePoint, StringEscaping stringEscapingStyle) {
   static const char hexDigits[] = "0123456789abcdef";
 
   out << "\\";
@@ -267,7 +267,7 @@ bool WriteAliasName(ostream_wrapper& out, const std::string& str) {
 }
 }  // namespace
 
-StringFormat::value ComputeStringFormat(const std::string& str,
+StringFormat ComputeStringFormat(const std::string& str,
                                         EMITTER_MANIP strFormat,
                                         FlowType flowType,
                                         bool escapeNonAscii) {
@@ -317,7 +317,7 @@ bool WriteSingleQuotedString(ostream_wrapper& out, const std::string& str) {
 }
 
 bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
-                             StringEscaping::value stringEscaping) {
+                             StringEscaping stringEscaping) {
   out << "\"";
   int codePoint;
   for (std::string::const_iterator i = str.begin();
@@ -379,7 +379,7 @@ bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
   return true;
 }
 
-bool WriteChar(ostream_wrapper& out, char ch, StringEscaping::value stringEscapingStyle) {
+bool WriteChar(ostream_wrapper& out, char ch, StringEscaping stringEscapingStyle) {
   if (('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z')) {
     out << ch;
   } else if (ch == '\"') {
diff --git a/src/emitterutils.h b/src/emitterutils.h
index 54fc12b..33cfd0e 100644
--- a/src/emitterutils.h
+++ b/src/emitterutils.h
@@ -20,27 +20,27 @@ class ostream_wrapper;
 namespace YAML {
 class Binary;
 
-struct StringFormat {
-  enum value { Plain, SingleQuoted, DoubleQuoted, Literal };
+enum class StringFormat {
+  Plain, SingleQuoted, DoubleQuoted, Literal
 };
 
-struct StringEscaping {
-  enum value { None, NonAscii, JSON };
+enum class StringEscaping {
+  None, NonAscii, JSON
 };
 
 namespace Utils {
-StringFormat::value ComputeStringFormat(const std::string& str,
+StringFormat ComputeStringFormat(const std::string& str,
                                         EMITTER_MANIP strFormat,
                                         FlowType flowType,
                                         bool escapeNonAscii);
 
 bool WriteSingleQuotedString(ostream_wrapper& out, const std::string& str);
 bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
-                             StringEscaping::value stringEscaping);
+                             StringEscaping stringEscaping);
 bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
                         std::size_t indent);
 bool WriteChar(ostream_wrapper& out, char ch,
-               StringEscaping::value stringEscapingStyle);
+               StringEscaping stringEscapingStyle);
 bool WriteComment(ostream_wrapper& out, const std::string& str,
                   std::size_t postCommentIndent);
 bool WriteAlias(ostream_wrapper& out, const std::string& str);