1 files changed, 1 insertions, 1 deletions
diff --git a/unicode.h b/unicode.h
index 7513be4a..6c488970 100644
--- a/unicode.h
+++ b/unicode.h
@@ -58,6 +58,6 @@ codepoint_flags unicode_cpt_flags(const std::string & utf8);
 std::string unicode_byte_to_utf8(uint8_t byte);
 uint8_t unicode_utf8_to_byte(const std::string & utf8);
 
-char32_t unicode_tolower(char32_t cp);
+uint32_t unicode_tolower(uint32_t cp);
 
 std::vector<std::string> unicode_regex_split(const std::string & text, const std::vector<std::string> & regex_exprs);