diff --git a/lib/parser/utils.cc b/lib/parser/utils.cc
index f4db03a2..3f9ffa5c 100644
--- a/lib/parser/utils.cc
+++ b/lib/parser/utils.cc
@@ -99,37 +99,33 @@ gx_utf8_flatten (const gchar *str, gssize len)
 
 } // namespace
 
-
 std::string // gx_utf8_flatten
-Mux::utf8_flatten (const std::string& str)
+Mux::utf8_flatten (const char *str)
 {
-	// optimization for boring old ascii strings
+	if (!str)
+		return {};
+
 	bool is_ascii = true;
-	std::string s{str};
-	for (auto it = s.begin(); it != s.end(); ++it) {
-		if (*it & 0x80) {
-			is_ascii = false;
-			break;
-		} else
-			*it = tolower(*it);
+	while (*str && is_ascii) {
+		is_ascii = *str & 0x80;
+		++str;
 	}
 
 	if (G_LIKELY(is_ascii))
-		return s;
+		return str;
 	///////////////////////////////////////////
 
 	// seems we need the big guns
-	char *flat = gx_utf8_flatten (str.c_str(), str.length());
+	char *flat = gx_utf8_flatten (str, -1);
 	if (!flat)
 		return {};
 
-	s = flat;
+	std::string s{flat};
 	g_free (flat);
 
 	return s;
 }
 
-
 std::string
 Mux::utf8_clean (const std::string& dirty)
 {
@@ -166,7 +162,6 @@ Mux::split (const std::string& str, const std::string& sepa)
 	return vec;
 }
 
-
 std::string
 Mux::quote (const std::string& str)
 {
@@ -222,7 +217,6 @@ Mux::date_to_time_t_string (int64_t t)
 	return buf;
 }
 
-
 static std::string
 delta_ymwdhMs (const std::string& expr)
 {
@@ -379,7 +373,6 @@ Mux::date_to_time_t_string (const std::string& dstr, bool is_first)
 		return date_to_time_t_string (t);
 }
 
-
 constexpr const auto SizeFormat = "%010" G_GINT64_FORMAT;
 
 constexpr const char SizeMin[] = "0000000000";
diff --git a/lib/parser/utils.hh b/lib/parser/utils.hh
index 71488de8..f243cdbf 100644
--- a/lib/parser/utils.hh
+++ b/lib/parser/utils.hh
@@ -32,7 +32,9 @@ namespace Mux {
  *
  * @return a flattened string
  */
-std::string utf8_flatten (const std::string& str);
+std::string utf8_flatten (const char *str);
+inline std::string utf8_flatten (const std::string& s) { return utf8_flatten(s.c_str()); }
+
 
 
 /**