diff --git a/parse-options.h b/parse-options.h
index 7d83e29..c95cbe2 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -136,6 +136,7 @@ struct option {
 #define OPT_BOOL_F(s, l, v, h, f)   OPT_SET_INT_F(s, l, v, h, 1, f)
 #define OPT_CALLBACK_F(s, l, v, a, h, f, cb)			\
 	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), (cb) }
+#define OPT_STRING_F(s, l, v, a, h, f)   { OPTION_STRING,  (s), (l), (v), (a), (h), (f) }
 
 #define OPT_END()                   { OPTION_END }
 #define OPT_ARGUMENT(l, h)          { OPTION_ARGUMENT, 0, (l), NULL, NULL, \
@@ -157,7 +158,7 @@ struct option {
 #define OPT_INTEGER(s, l, v, h)     { OPTION_INTEGER, (s), (l), (v), N_("n"), (h) }
 #define OPT_MAGNITUDE(s, l, v, h)   { OPTION_MAGNITUDE, (s), (l), (v), \
 				      N_("n"), (h), PARSE_OPT_NONEG }
-#define OPT_STRING(s, l, v, a, h)   { OPTION_STRING,  (s), (l), (v), (a), (h) }
+#define OPT_STRING(s, l, v, a, h)   OPT_STRING_F(s, l, v, a, h, 0)
 #define OPT_STRING_LIST(s, l, v, a, h) \
 				    { OPTION_CALLBACK, (s), (l), (v), (a), \
 				      (h), 0, &parse_opt_string_list }