diff --git a/cpp/utilities.cpp b/cpp/utilities.cpp
index b44afc5..95e0300 100644
--- a/cpp/utilities.cpp
+++ b/cpp/utilities.cpp
@@ -459,8 +459,8 @@ void create_tarball(const std::string &tarball_path,
             if (stat(top_dir.c_str(), &file_stat) == 0) {
                 std::string uname = clean_utf8(getpwuid(file_stat.st_uid) ? getpwuid(file_stat.st_uid)->pw_name : "lugito");
                 std::string gname = clean_utf8(getgrgid(file_stat.st_gid) ? getgrgid(file_stat.st_gid)->gr_name : "lugito");
-                archive_entry_set_uname(entry, uname);
-                archive_entry_set_gname(entry, gname);
+                archive_entry_set_uname(entry, uname.c_str());
+                archive_entry_set_gname(entry, gname.c_str());
                 archive_entry_set_uid(entry, file_stat.st_uid);
                 archive_entry_set_gid(entry, file_stat.st_gid);
                 archive_entry_set_perm(entry, file_stat.st_mode);
@@ -534,8 +534,8 @@ void create_tarball(const std::string &tarball_path,
             if (stat(path.c_str(), &file_stat) == 0) {
                 std::string uname = clean_utf8(getpwuid(file_stat.st_uid) ? getpwuid(file_stat.st_uid)->pw_name : "lugito");
                 std::string gname = clean_utf8(getgrgid(file_stat.st_gid) ? getgrgid(file_stat.st_gid)->gr_name : "lugito");
-                archive_entry_set_uname(entry, uname);
-                archive_entry_set_gname(entry, gname);
+                archive_entry_set_uname(entry, uname.c_str());
+                archive_entry_set_gname(entry, gname.c_str());
                 archive_entry_set_uid(entry, file_stat.st_uid);
                 archive_entry_set_gid(entry, file_stat.st_gid);
                 archive_entry_set_perm(entry, file_stat.st_mode);