diff --git a/include/tclap/Arg.h b/include/tclap/Arg.h
index 7725de9..095d510 100644
--- a/include/tclap/Arg.h
+++ b/include/tclap/Arg.h
@@ -485,7 +485,7 @@ inline void Arg::setRequireLabel( const std::string& s)
 
 inline bool Arg::argMatches( const std::string& argFlag ) const
 {
-	if ( argFlag == Arg::flagStartString() + _flag ||
+	if ( ( argFlag == Arg::flagStartString() + _flag && _flag != "" ) ||
 		 argFlag == Arg::nameStartString() + _name )
 		return true;
 	else