diff --git a/include/argparse/argparse.hpp b/include/argparse/argparse.hpp
index a779e014..539bdf72 100644
--- a/include/argparse/argparse.hpp
+++ b/include/argparse/argparse.hpp
@@ -683,7 +683,7 @@ class Argument {
     auto hspace = "  "; // minimal space between name and help message
     stream << name_stream.str();
     std::string_view help_view(argument.m_help);
-    while ((pos = argument.m_help.find('\n', prev)) != std::string::npos) {
+    while ((pos = argument.m_help.find('\n', prev)) != (signed)std::string::npos) {
       auto line = help_view.substr(prev, pos - prev + 1);
       if (first_line) {
         stream << hspace << line;