diff --git a/src/common/options.c b/src/common/options.c
--- a/src/common/options.c
+++ b/src/common/options.c
@@ -52,7 +52,7 @@ int options_init(int argc, char *argv[],
   char curopt;
 
   configfileprefix = NULL;
-  while((curopt = getopt(argc, argv, optstring)) != -1)
+  while((curopt = getopt(argc, argv, optstring)) != (char)-1)
     switch(curopt)
       {
       case 'h':