diff --git a/src/emitterutils.cpp b/src/emitterutils.cpp
index 93c2f9b..147738a 100644
--- a/src/emitterutils.cpp
+++ b/src/emitterutils.cpp
@@ -354,7 +354,7 @@ bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
 }
 
 bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
-                        int indent) {
+                        std::size_t indent) {
   out << "|\n";
   out << IndentTo(indent);
   int codePoint;
@@ -393,7 +393,7 @@ bool WriteChar(ostream_wrapper& out, char ch) {
 }
 
 bool WriteComment(ostream_wrapper& out, const std::string& str,
-                  int postCommentIndent) {
+                  std::size_t postCommentIndent) {
   const std::size_t curIndent = out.col();
   out << "#" << Indentation(postCommentIndent);
   out.set_comment();
diff --git a/src/emitterutils.h b/src/emitterutils.h
index 3a9c2f8..6cc7319 100644
--- a/src/emitterutils.h
+++ b/src/emitterutils.h
@@ -34,10 +34,10 @@ bool WriteSingleQuotedString(ostream_wrapper& out, const std::string& str);
 bool WriteDoubleQuotedString(ostream_wrapper& out, const std::string& str,
                              bool escapeNonAscii);
 bool WriteLiteralString(ostream_wrapper& out, const std::string& str,
-                        int indent);
+                        std::size_t indent);
 bool WriteChar(ostream_wrapper& out, char ch);
 bool WriteComment(ostream_wrapper& out, const std::string& str,
-                  int postCommentIndent);
+                  std::size_t postCommentIndent);
 bool WriteAlias(ostream_wrapper& out, const std::string& str);
 bool WriteAnchor(ostream_wrapper& out, const std::string& str);
 bool WriteTag(ostream_wrapper& out, const std::string& str, bool verbatim);