--- stag/stag.c	2016-08-31 15:03:32.627902972 +0200
+++ stag.c	2016-08-31 15:18:34.487902628 +0200
@@ -87,7 +87,7 @@
   
 
   // Read options
-  char opt;
+  signed char opt;
   int option_index = 0;
   struct option long_options[] =
   {