diff --git a/main.cpp b/main.cpp
index 0b1e78a..d41f78c 100644
--- a/main.cpp
+++ b/main.cpp
@@ -74,7 +74,7 @@ public:
         {0, 0, 0, 0}
       };
       int option_index = 0;
-      int c = getopt_long(argc, argv, "h:n:m:t:p:d:o:i:k:", long_options, &option_index);
+      int c = getopt_long(argc, argv, "h:n:m:t:p:d:o:i:k:w:", long_options, &option_index);
       if (c == -1) break;
       switch (c) {
         case 'h': {