diff --git a/libcxx/include/charconv b/libcxx/include/charconv
--- a/libcxx/include/charconv
+++ b/libcxx/include/charconv
@@ -107,8 +107,8 @@
 
 #ifndef _LIBCPP_CXX03_LANG
 
-void to_chars(char*, char*, bool, int = 10) = delete;
-void from_chars(const char*, const char*, bool, int = 10) = delete;
+to_chars_result to_chars(char*, char*, bool, int = 10) = delete;
+from_chars_result from_chars(const char*, const char*, bool, int = 10) = delete;
 
 namespace __itoa
 {