diff --git a/activitypub.c b/activitypub.c
index f4b4eac..6e40a88 100644
--- a/activitypub.c
+++ b/activitypub.c
@@ -163,7 +163,7 @@ const char *get_atto(const xs_dict *msg)
     if (xs_type(actor) == XSTYPE_LIST) {
         const xs_list *p = actor;
         int c = 0;
-        xs_dict *v;
+        const xs_dict *v;
         actor = NULL;
 
         while (actor == NULL && xs_list_next(p, &v, &c)) {
@@ -192,7 +192,7 @@ xs_list *get_attachments(const xs_dict *msg)
     /* try first the attachments list */
     if (!xs_is_null(p = xs_dict_get(msg, "attachment"))) {
         xs *attach = NULL;
-        xs_val *v;
+        const xs_val *v;
 
         /* ensure it's a list */
         if (xs_type(p) == XSTYPE_DICT) {
@@ -257,7 +257,7 @@ xs_list *get_attachments(const xs_dict *msg)
         const char *href = NULL;
         const char *type = NULL;
         int c = 0;
-        xs_val *v;
+        const xs_val *v;
 
         while (href == NULL && xs_list_next(p, &v, &c)) {
             if (xs_type(v) == XSTYPE_DICT) {
@@ -271,7 +271,7 @@ xs_list *get_attachments(const xs_dict *msg)
                         strcmp(mtype, "application/x-mpegURL") == 0 &&
                         xs_type(tag) == XSTYPE_LIST) {
                         /* now iterate the tag list, looking for a video URL */
-                        xs_dict *d;
+                        const xs_dict *d;
                         int c = 0;
 
                         while (href == NULL && xs_list_next(tag, &d, &c)) {
@@ -482,7 +482,7 @@ xs_list *recipient_list(snac *snac, const xs_dict *msg, int expand_public)
     const xs_list *lists[] = { to, cc, NULL };
     for (n = 0; lists[n]; n++) {
         xs_list *l = (xs_list *)lists[n];
-        char *v;
+        const char *v;
         xs *tl = NULL;
 
         /* if it's a string, create a list with only one element */
@@ -497,7 +497,7 @@ xs_list *recipient_list(snac *snac, const xs_dict *msg, int expand_public)
             if (expand_public && strcmp(v, public_address) == 0) {
                 /* iterate the followers and add them */
                 xs *fwers = follower_list(snac);
-                char *actor;
+                const char *actor;
 
                 char *p = fwers;
                 while (xs_list_iter(&p, &actor))
@@ -628,7 +628,7 @@ int is_msg_for_me(snac *snac, const xs_dict *c_msg)
     const xs_dict *msg = xs_dict_get(c_msg, "object");
     xs *rcpts = recipient_list(snac, msg, 0);
     xs_list *p = rcpts;
-    xs_str *v;
+    const xs_str *v;
 
     xs *actor_followers = NULL;
 
@@ -693,7 +693,7 @@ xs_str *process_tags(snac *snac, const char *content, xs_list **tag)
     xs_list *tl = *tag;
     xs *split;
     xs_list *p;
-    xs_val *v;
+    const xs_val *v;
     int n = 0;
 
     /* create a default server for incomplete mentions */
@@ -1205,8 +1205,8 @@ xs_dict *msg_actor(snac *snac)
     const xs_dict *metadata = xs_dict_get(snac->config, "metadata");
     if (xs_type(metadata) == XSTYPE_DICT) {
         xs *attach = xs_list_new();
-        xs_str *k;
-        xs_str *v;
+        const xs_str *k;
+        const xs_str *v;
 
         int c = 0;
         while (xs_dict_next(metadata, &k, &v, &c)) {
@@ -1351,7 +1351,7 @@ xs_dict *msg_note(snac *snac, const xs_str *content, const xs_val *rcpts,
     xs *atls = xs_list_new();
     xs_dict *msg = msg_base(snac, "Note", id, NULL, "@now", NULL);
     xs_list *p;
-    xs_val *v;
+    const xs_val *v;
 
     if (rcpts == NULL)
         to = xs_list_new();
@@ -1528,7 +1528,7 @@ xs_dict *msg_question(snac *user, const char *content, xs_list *attach,
 
     xs *o = xs_list_new();
     xs_list *p = (xs_list *)opts;
-    xs_str *v;
+    const xs_str *v;
     xs *replies = xs_json_loads("{\"type\":\"Collection\",\"totalItems\":0}");
 
     xs_set_init(&seen);
@@ -1576,7 +1576,7 @@ int update_question(snac *user, const char *id)
     xs *lopts = xs_list_new();
     const xs_list *opts;
     xs_list *p;
-    xs_val *v;
+    const xs_val *v;
 
     /* get the object */
     if (!valid_status(object_get(id, &msg)))
@@ -2190,7 +2190,7 @@ void process_user_queue_item(snac *snac, xs_dict *q_item)
         xs *rcpts    = recipient_list(snac, msg, 1);
         xs_set inboxes;
         xs_list *p;
-        xs_str *actor;
+        const xs_str *actor;
 
         xs_set_init(&inboxes);
 
@@ -2212,7 +2212,7 @@ void process_user_queue_item(snac *snac, xs_dict *q_item)
         if (is_msg_public(msg)) {
             if (xs_type(xs_dict_get(srv_config, "disable_inbox_collection")) != XSTYPE_TRUE) {
                 xs *shibx = inbox_list();
-                xs_str *inbox;
+                const xs_str *inbox;
 
                 p = shibx;
                 while (xs_list_iter(&p, &inbox)) {
@@ -2304,7 +2304,7 @@ int process_user_queue(snac *snac)
     xs *list = user_queue(snac);
 
     xs_list *p = list;
-    xs_str *fn;
+    const xs_str *fn;
 
     while (xs_list_iter(&p, &fn)) {
         xs *q_item = dequeue(fn);
@@ -2511,7 +2511,7 @@ void process_queue_item(xs_dict *q_item)
 
             xs *users = user_list();
             xs_list *p = users;
-            char *v;
+            const char *v;
             int cnt = 0;
 
             while (xs_list_iter(&p, &v)) {
@@ -2554,7 +2554,7 @@ int process_queue(void)
     xs *list = queue();
 
     xs_list *p = list;
-    xs_str *fn;
+    const xs_str *fn;
 
     while (xs_list_iter(&p, &fn)) {
         xs *q_item = dequeue(fn);
@@ -2616,7 +2616,8 @@ int activitypub_get_handler(const xs_dict *req, const char *q_path,
         xs *elems = timeline_simple_list(&snac, "public", 0, 20);
         xs *list = xs_list_new();
         msg = msg_collection(&snac, id);
-        char *p, *v;
+        char *p;
+        const char *v;
 
         p = elems;
         while (xs_list_iter(&p, &v)) {
diff --git a/data.c b/data.c
index 6ac115d..f507078 100644
--- a/data.c
+++ b/data.c
@@ -193,7 +193,7 @@ int user_open(snac *user, const char *uid)
             xs *lcuid = xs_tolower_i(xs_dup(uid));
             xs *ulist = user_list();
             xs_list *p = ulist;
-            xs_str *v;
+            const xs_str *v;
 
             while (xs_list_iter(&p, &v)) {
                 xs *v2 = xs_tolower_i(xs_dup(v));
@@ -289,7 +289,7 @@ int user_open_by_md5(snac *snac, const char *md5)
 {
     xs *ulist  = user_list();
     xs_list *p = ulist;
-    xs_str *v;
+    const xs_str *v;
 
     while (xs_list_iter(&p, &v)) {
         user_open(snac, v);
@@ -772,7 +772,8 @@ int object_del_by_md5(const char *md5)
         xs *spec  = xs_dup(fn);
         spec      = xs_replace_i(spec, ".json", "*.idx");
         xs *files = xs_glob(spec, 0, 0);
-        char *p, *v;
+        char *p;
+        const char *v;
 
         p = files;
         while (xs_list_iter(&p, &v)) {
@@ -1033,7 +1034,8 @@ xs_list *follower_list(snac *snac)
 {
     xs *list       = object_user_cache_list(snac, "followers", XS_ALL, 0);
     xs_list *fwers = xs_list_new();
-    char *p, *v;
+    char *p;
+    const char *v;
 
     /* resolve the list of md5 to be a list of actors */
     p = list;
@@ -1196,7 +1198,7 @@ xs_list *timeline_top_level(snac *snac, const xs_list *list)
 /* returns the top level md5 entries from this index */
 {
     xs_set seen;
-    xs_str *v;
+    const xs_str *v;
 
     xs_set_init(&seen);
 
@@ -1367,7 +1369,7 @@ xs_list *following_list(snac *snac)
     xs *spec = xs_fmt("%s/following/" "*.json", snac->basedir);
     xs *glist = xs_glob(spec, 0, 0);
     xs_list *p;
-    xs_str *v;
+    const xs_str *v;
     xs_list *list = xs_list_new();
 
     /* iterate the list of files */
@@ -1537,7 +1539,8 @@ void hide(snac *snac, const char *id)
 
         /* hide all the children */
         xs *chld = object_children(id);
-        char *p, *v;
+        char *p;
+        const char *v;
 
         p = chld;
         while (xs_list_iter(&p, &v)) {
@@ -1694,7 +1697,7 @@ void tag_index(const char *id, const xs_dict *obj)
 
         mkdirx(g_tag_dir);
 
-        xs_dict *v;
+        const xs_dict *v;
         int ct = 0;
         while (xs_list_next(tags, &v, &ct)) {
             const char *type = xs_dict_get(v, "type");
@@ -1758,7 +1761,7 @@ xs_val *list_maint(snac *user, const char *list, int op)
             xs *spec = xs_fmt("%s/list/" "*.id", user->basedir);
             xs *ls   = xs_glob(spec, 0, 0);
             int c = 0;
-            char *v;
+            const char *v;
 
             l = xs_list_new();
 
@@ -1784,7 +1787,7 @@ xs_val *list_maint(snac *user, const char *list, int op)
         {
             xs *lol = list_maint(user, NULL, 0);
             int c = 0;
-            xs_list *v;
+            const xs_list *v;
             int add = 1;
 
             /* check if this list name already exists */
@@ -1925,7 +1928,7 @@ void list_distribute(snac *user, const char *who, const xs_dict *post)
         xs *spec  = xs_fmt("%s/list/" "*.lst", user->basedir);
         xs *ls    = xs_glob(spec, 0, 0);
         int c = 0;
-        char *v;
+        const char *v;
 
         while (xs_list_next(ls, &v, &c)) {
             /* is the actor in this list? */
@@ -2183,7 +2186,7 @@ xs_list *inbox_list(void)
     xs *spec     = xs_fmt("%s/inbox/" "*", srv_basedir);
     xs *files    = xs_glob(spec, 0, 0);
     xs_list *p   = files;
-    xs_val *v;
+    const xs_val *v;
 
     while (xs_list_iter(&p, &v)) {
         FILE *f;
@@ -2329,8 +2332,8 @@ xs_list *content_search(snac *user, const char *regex,
 
     /* iterate all timelines simultaneously */
     xs_list *tls[3] = {0};
-    char *md5s[3]   = {0};
-    int c[3]        = {0};
+    const char *md5s[3] = {0};
+    int c[3] = {0};
 
     tls[0] = timeline_simple_list(user, "public", 0, XS_ALL);   /* public */
     tls[1] = timeline_instance_list(0, XS_ALL); /* instance */
@@ -2368,7 +2371,7 @@ xs_list *content_search(snac *user, const char *regex,
         if (newest == -1)
             break;
 
-        char *md5 = md5s[newest];
+        const char *md5 = md5s[newest];
 
         /* advance the chosen timeline */
         if (!xs_list_next(tls[newest], &md5s[newest], &c[newest]))
@@ -2534,7 +2537,7 @@ xs_list *notify_list(snac *snac, int skip, int show)
             xs *spec = xs_fmt("%s/notify/" "*.json", snac->basedir);
             xs *lst  = xs_glob(spec, 1, 0);
             xs_list *p = lst;
-            char *v;
+            const char *v;
 
             while (xs_list_iter(&p, &v)) {
                 char *p = strrchr(v, '.');
@@ -2562,7 +2565,7 @@ int notify_new_num(snac *snac)
     int cnt = 0;
 
     xs_list *p = lst;
-    xs_str *v;
+    const xs_str *v;
 
     while (xs_list_iter(&p, &v)) {
         xs *id = xs_strip_i(xs_dup(v));
@@ -2584,7 +2587,7 @@ void notify_clear(snac *snac)
     xs *spec   = xs_fmt("%s/notify/" "*", snac->basedir);
     xs *lst    = xs_glob(spec, 0, 0);
     xs_list *p = lst;
-    xs_str *v;
+    const xs_str *v;
 
     while (xs_list_iter(&p, &v))
         unlink(v);
@@ -2842,7 +2845,7 @@ int was_question_voted(snac *user, const char *id)
     xs *children = object_children(id);
     int voted = 0;
     xs_list *p;
-    xs_str *md5;
+    const xs_str *md5;
 
     p = children;
     while (xs_list_iter(&p, &md5)) {
@@ -2869,7 +2872,7 @@ xs_list *user_queue(snac *snac)
     xs_list *list = xs_list_new();
     time_t t      = time(NULL);
     xs_list *p;
-    xs_val *v;
+    const xs_val *v;
 
     xs *fns = xs_glob(spec, 0, 0);
 
@@ -2898,7 +2901,7 @@ xs_list *queue(void)
     xs_list *list = xs_list_new();
     time_t t      = time(NULL);
     xs_list *p;
-    xs_val *v;
+    const xs_val *v;
 
     xs *fns = xs_glob(spec, 0, 0);
 
@@ -2974,7 +2977,7 @@ static void _purge_dir(const char *dir, int days)
         xs *spec  = xs_fmt("%s/" "*", dir);
         xs *list  = xs_glob(spec, 0, 0);
         xs_list *p;
-        xs_str *v;
+        const xs_str *v;
 
         p = list;
         while (xs_list_iter(&p, &v))
@@ -3000,7 +3003,7 @@ void purge_server(void)
     xs *spec = xs_fmt("%s/object/??", srv_basedir);
     xs *dirs = xs_glob(spec, 0, 0);
     xs_list *p;
-    xs_str *v;
+    const xs_str *v;
     int cnt = 0;
     int icnt = 0;
 
@@ -3009,7 +3012,7 @@ void purge_server(void)
     p = dirs;
     while (xs_list_iter(&p, &v)) {
         xs_list *p2;
-        xs_str *v2;
+        const xs_str *v2;
 
         {
             xs *spec2 = xs_fmt("%s/" "*.json", v);
@@ -3088,7 +3091,7 @@ void purge_server(void)
         xs *spec2 = xs_fmt("%s/" "*.idx", v);
         xs *files = xs_glob(spec2, 0, 0);
         xs_list *p2;
-        xs_str *v2;
+        const xs_str *v2;
 
         p2 = files;
         while (xs_list_iter(&p2, &v2)) {
@@ -3152,7 +3155,7 @@ void purge_user(snac *snac)
         xs *spec = xs_fmt("%s/list/" "*.idx", snac->basedir);
         xs *lol  = xs_glob(spec, 0, 0);
         int c = 0;
-        char *v;
+        const char *v;
 
         while (xs_list_next(lol, &v, &c)) {
             int gc = index_gc(v);
@@ -3170,7 +3173,8 @@ void purge_all(void)
 {
     snac snac;
     xs *list = user_list();
-    char *p, *uid;
+    char *p;
+    const char *uid;
 
     p = list;
     while (xs_list_iter(&p, &uid)) {
diff --git a/format.c b/format.c
index df3b5d9..b021f55 100644
--- a/format.c
+++ b/format.c
@@ -82,7 +82,8 @@ static xs_str *format_line(const char *line, xs_list **attach)
 /* formats a line */
 {
     xs_str *s = xs_str_new(NULL);
-    char *p, *v;
+    char *p;
+    const char *v;
 
     /* split by markup */
     xs *sm = xs_regex_split(line,
@@ -155,7 +156,8 @@ xs_str *not_really_markdown(const char *content, xs_list **attach, xs_list **tag
     int in_pre = 0;
     int in_blq = 0;
     xs *list;
-    char *p, *v;
+    char *p;
+    const char *v;
 
     /* work by lines */
     list = xs_split(content, "\n");
@@ -234,7 +236,7 @@ xs_str *not_really_markdown(const char *content, xs_list **attach, xs_list **tag
         /* traditional emoticons */
         xs *d = emojis();
         int c = 0;
-        char *k, *v;
+        const char *k, *v;
 
         while (xs_dict_next(d, &k, &v, &c)) {
             const char *t = NULL;
@@ -280,7 +282,8 @@ xs_str *sanitize(const char *content)
     xs_str *s = xs_str_new(NULL);
     xs *sl;
     int n = 0;
-    char *p, *v;
+    char *p;
+    const char *v;
 
     sl = xs_regex_split(content, "</?[^>]+>");
 
diff --git a/html.c b/html.c
index 6521726..11fe4bf 100644
--- a/html.c
+++ b/html.c
@@ -57,7 +57,7 @@ xs_str *replace_shortnames(xs_str *s, const xs_list *tag, int ems)
 
         xs *style = xs_fmt("height: %dem; width: %dem; vertical-align: middle;", ems, ems);
 
-        char *v;
+        const char *v;
         int c = 0;
 
         while (xs_list_next(tag_list, &v, &c)) {
@@ -461,7 +461,7 @@ static xs_html *html_base_head(void)
     xs *f;
     f = xs_fmt("%s/favicon.ico", srv_baseurl);
     const xs_list *p = xs_dict_get(srv_config, "cssurls");
-    char *v;
+    const char *v;
     int c = 0;
 
     while (xs_list_next(p, &v, &c)) {
@@ -801,8 +801,8 @@ static xs_html *html_user_body(snac *user, int read_only)
 
         const xs_dict *metadata = xs_dict_get(user->config, "metadata");
         if (xs_type(metadata) == XSTYPE_DICT) {
-            xs_str *k;
-            xs_str *v;
+            const xs_str *k;
+            const xs_str *v;
 
             xs_dict *val_links = user->links;
             if (xs_is_null(val_links))
@@ -974,8 +974,8 @@ xs_html *html_top_controls(snac *snac)
 
     xs *metadata = xs_str_new(NULL);
     const xs_dict *md = xs_dict_get(snac->config, "metadata");
-    xs_str *k;
-    xs_str *v;
+    const xs_str *k;
+    const xs_str *v;
 
     int c = 0;
     while (xs_dict_next(md, &k, &v, &c)) {
@@ -1161,7 +1161,7 @@ xs_str *build_mentions(snac *snac, const xs_dict *msg)
 {
     xs_str *s = xs_str_new(NULL);
     const char *list = xs_dict_get(msg, "tag");
-    char *v;
+    const char *v;
     int c = 0;
 
     while (xs_list_next(list, &v, &c)) {
@@ -1372,7 +1372,7 @@ xs_html *html_entry_controls(snac *snac, const char *actor,
 
 
 xs_html *html_entry(snac *user, xs_dict *msg, int read_only,
-                   int level, char *md5, int hide_children)
+                   int level, const char *md5, int hide_children)
 {
     const char *id    = xs_dict_get(msg, "id");
     const char *type  = xs_dict_get(msg, "type");
@@ -1670,7 +1670,7 @@ xs_html *html_entry(snac *user, xs_dict *msg, int read_only,
         const xs_list *oo = xs_dict_get(msg, "oneOf");
         const xs_list *ao = xs_dict_get(msg, "anyOf");
         const xs_list *p;
-        xs_dict *v;
+        const xs_dict *v;
         int closed = 0;
         const char *f_closed = NULL;
 
@@ -1827,7 +1827,7 @@ xs_html *html_entry(snac *user, xs_dict *msg, int read_only,
             content_attachments);
 
         int c = 0;
-        xs_dict *a;
+        const xs_dict *a;
         while (xs_list_next(attach, &a, &c)) {
             const char *type = xs_dict_get(a, "type");
             const char *href = xs_dict_get(a, "href");
@@ -1945,7 +1945,7 @@ xs_html *html_entry(snac *user, xs_dict *msg, int read_only,
             }
 
             xs_list *p = children;
-            char *cmd5;
+            const char *cmd5;
             int cnt = 0;
             int o_cnt = 0;
 
@@ -2021,7 +2021,7 @@ xs_str *html_timeline(snac *user, const xs_list *list, int read_only,
 /* returns the HTML for the timeline */
 {
     xs_list *p = (xs_list *)list;
-    char *v;
+    const char *v;
     double t = ftime();
 
     xs *desc = NULL;
@@ -2130,7 +2130,7 @@ xs_str *html_timeline(snac *user, const xs_list *list, int read_only,
 
             xs *list = history_list(user);
             xs_list *p = list;
-            char *v;
+            const char *v;
 
             while (xs_list_iter(&p, &v)) {
                 xs *fn  = xs_replace(v, ".html", "");
@@ -2203,7 +2203,7 @@ xs_html *html_people_list(snac *snac, xs_list *list, char *header, char *t)
                     xs_html_text("..."))));
 
     xs_list *p = list;
-    char *actor_id;
+    const char *actor_id;
 
     while (xs_list_iter(&p, &actor_id)) {
         xs *md5 = xs_md5_hex(actor_id, strlen(actor_id));
@@ -2363,7 +2363,7 @@ xs_str *html_notifications(snac *user, int skip, int show)
     xs_html *noti_seen = NULL;
 
     xs_list *p = n_list;
-    xs_str *v;
+    const xs_str *v;
     while (xs_list_iter(&p, &v)) {
         xs *noti = notify_get(user, v);
 
@@ -3232,7 +3232,7 @@ int html_post_handler(const xs_dict *req, const char *q_path,
             xs_dict *md = xs_dict_new();
             xs *l = xs_split(v, "\n");
             xs_list *p = l;
-            xs_str *kp;
+            const xs_str *kp;
 
             while (xs_list_iter(&p, &kp)) {
                 xs *kpl = xs_split_n(kp, "=", 1);
@@ -3333,7 +3333,7 @@ int html_post_handler(const xs_dict *req, const char *q_path,
         }
 
         xs_list *p = ls;
-        xs_str *v;
+        const xs_str *v;
 
         while (xs_list_iter(&p, &v)) {
             xs *msg = msg_note(&snac, "", actor, irt, NULL, 1);
@@ -3405,7 +3405,7 @@ xs_str *timeline_to_rss(snac *user, const xs_list *timeline, char *title, char *
     xs_html_add(rss, channel);
 
     int c = 0;
-    char *v;
+    const char *v;
 
     while (xs_list_next(timeline, &v, &c)) {
         xs *msg = NULL;
diff --git a/http.c b/http.c
index 4d85631..b21f1dc 100644
--- a/http.c
+++ b/http.c
@@ -26,7 +26,7 @@ xs_dict *http_signed_request_raw(const char *keyid, const char *seckey,
     xs *hdrs = NULL;
     const char *host;
     const char *target;
-    char *k, *v;
+    const char *k, *v;
     xs_dict *response;
 
     date = xs_str_utctime(0, "%a, %d %b %Y %H:%M:%S GMT");
@@ -144,7 +144,7 @@ int check_signature(const xs_dict *req, xs_str **err)
         /* extract the values */
         xs *l = xs_split(sig_hdr, ",");
         int c = 0;
-        xs_val *v;
+        const xs_val *v;
 
         while (xs_list_next(l, &v, &c)) {
             xs *kv = xs_split_n(v, "=", 1);
@@ -205,7 +205,7 @@ int check_signature(const xs_dict *req, xs_str **err)
     {
         xs *l = xs_split(headers, " ");
         xs_list *p;
-        xs_val *v;
+        const xs_val *v;
 
         p = l;
         while (xs_list_iter(&p, &v)) {
diff --git a/httpd.c b/httpd.c
index 8a20c89..a7396e8 100644
--- a/httpd.c
+++ b/httpd.c
@@ -75,7 +75,7 @@ xs_str *nodeinfo_2_0(void)
     int n_posts  = 0;
     xs *users = user_list();
     xs_list *p = users;
-    char *v;
+    const char *v;
     double now = (double)time(NULL);
 
     while (xs_list_iter(&p, &v)) {
@@ -128,7 +128,7 @@ static xs_str *greeting_html(void)
             const char *host = xs_dict_get(srv_config, "host");
             xs *list = user_list();
             xs_list *p = list;
-            xs_str *uid;
+            const xs_str *uid;
 
             xs_html *ul = xs_html_tag("ul",
                 xs_html_attr("class", "snac-user-list"));
@@ -413,7 +413,7 @@ void httpd_connection(FILE *f)
     /* if there are any additional headers, add them */
     const xs_dict *more_headers = xs_dict_get(srv_config, "http_headers");
     if (xs_type(more_headers) == XSTYPE_DICT) {
-        char *k, *v;
+        const char *k, *v;
         int c = 0;
         while (xs_dict_next(more_headers, &k, &v, &c))
             headers = xs_dict_set(headers, k, v);
@@ -590,7 +590,8 @@ static void *background_thread(void *arg)
 
         {
             xs *list = user_list();
-            char *p, *uid;
+            char *p;
+            const char *uid;
 
             /* process queues for all users */
             p = list;
diff --git a/main.c b/main.c
index 9c906a6..c88eebe 100644
--- a/main.c
+++ b/main.c
@@ -382,7 +382,7 @@ int main(int argc, char *argv[])
         xs *r = content_search(&snac, url, 1, 0, XS_ALL, 10, &to);
 
         int c = 0;
-        char *v;
+        const char *v;
 
         /* print results as standalone links */
         while (xs_list_next(r, &v, &c)) {
diff --git a/mastoapi.c b/mastoapi.c
index 852713e..3936c2a 100644
--- a/mastoapi.c
+++ b/mastoapi.c
@@ -599,7 +599,7 @@ xs_dict *mastoapi_account(const xs_dict *actor)
     const xs_list *p;
     if (!xs_is_null(p = xs_dict_get(actor, "tag"))) {
         xs *eml = xs_list_new();
-        xs_dict *v;
+        const xs_dict *v;
         int c = 0;
 
         while (xs_list_next(p, &v, &c)) {
@@ -637,7 +637,7 @@ xs_dict *mastoapi_account(const xs_dict *actor)
 
     xs *fields = xs_list_new();
     p = xs_dict_get(actor, "attachment");
-    xs_dict *v;
+    const xs_dict *v;
 
     /* dict of validated links */
     xs_dict *val_links = NULL;
@@ -713,7 +713,7 @@ xs_dict *mastoapi_poll(snac *snac, const xs_dict *msg)
     xs_dict *poll = xs_dict_new();
     xs *mid       = mastoapi_id(msg);
     const xs_list *opts = NULL;
-    xs_val *v;
+    const xs_val *v;
     int num_votes = 0;
     xs *options = xs_list_new();
 
@@ -849,7 +849,7 @@ xs_dict *mastoapi_status(snac *snac, const xs_dict *msg)
 
     {
         xs_list *p = attach;
-        xs_dict *v;
+        const xs_dict *v;
 
         xs *matt = xs_list_new();
 
@@ -898,7 +898,7 @@ xs_dict *mastoapi_status(snac *snac, const xs_dict *msg)
             tag_list = xs_list_new();
 
         tag = tag_list;
-        xs_dict *v;
+        const xs_dict *v;
 
         int c = 0;
         while (xs_list_next(tag, &v, &c)) {
@@ -1210,8 +1210,8 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
             const xs_dict *metadata = xs_dict_get(snac1.config, "metadata");
             if (xs_type(metadata) == XSTYPE_DICT) {
                 xs *fields = xs_list_new();
-                xs_str *k;
-                xs_str *v;
+                const xs_str *k;
+                const xs_str *v;
 
                 xs_dict *val_links = snac1.links;
                 if (xs_is_null(val_links))
@@ -1334,7 +1334,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                     xs *wers = follower_list(&snac1);
                     xs *ulst = user_list();
                     xs_list *p;
-                    xs_str *v;
+                    const xs_str *v;
                     xs_set seen;
 
                     xs_set_init(&seen);
@@ -1410,7 +1410,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                     /* the public list of posts of a user */
                     xs *timeline = timeline_simple_list(&snac2, "public", 0, 256);
                     xs_list *p   = timeline;
-                    xs_str *v;
+                    const xs_str *v;
 
                     out = xs_list_new();
 
@@ -1475,7 +1475,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
 
             xs *out      = xs_list_new();
             xs_list *p   = timeline;
-            xs_str *v;
+            const xs_str *v;
 
             while (xs_list_iter(&p, &v) && cnt < limit) {
                 xs *msg = NULL;
@@ -1579,7 +1579,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
         xs *timeline = timeline_instance_list(0, limit);
         xs *out      = xs_list_new();
         xs_list *p   = timeline;
-        xs_str *md5;
+        const xs_str *md5;
 
         snac *user = NULL;
         if (logged_in)
@@ -1633,7 +1633,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
         xs *timeline = tag_search(tag, 0, limit);
         xs *out      = xs_list_new();
         xs_list *p   = timeline;
-        xs_str *md5;
+        const xs_str *md5;
 
         while (xs_list_iter(&p, &md5) && cnt < limit) {
             xs *msg = NULL;
@@ -1673,7 +1673,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
             xs *timeline = list_timeline(&snac1, list, 0, 2048);
             xs *out      = xs_list_new();
             int c = 0;
-            char *md5;
+            const char *md5;
 
             while (xs_list_next(timeline, &md5, &c)) {
                 xs *msg = NULL;
@@ -1747,7 +1747,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
             xs *l      = notify_list(&snac1, 0, 64);
             xs *out    = xs_list_new();
             xs_list *p = l;
-            xs_dict *v;
+            const xs_dict *v;
             const xs_list *excl = xs_dict_get(args, "exclude_types[]");
 
             while (xs_list_iter(&p, &v)) {
@@ -1858,7 +1858,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
             xs *lol = list_maint(&snac1, NULL, 0);
             xs *l   = xs_list_new();
             int c = 0;
-            xs_list *li;
+            const xs_list *li;
 
             while (xs_list_next(lol, &li, &c)) {
                 xs *d = xs_dict_new();
@@ -1890,7 +1890,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                         xs *actors = list_content(&snac1, p, NULL, 0);
                         xs *out = xs_list_new();
                         int c = 0;
-                        char *v;
+                        const char *v;
 
                         while (xs_list_next(actors, &v, &c)) {
                             xs *actor = NULL;
@@ -1911,7 +1911,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                     xs *out = xs_list_new();
                     xs *lol = list_maint(&snac1, NULL, 0);
                     int c = 0;
-                    xs_list *v;
+                    const xs_list *v;
 
                     while (xs_list_next(lol, &v, &c)) {
                         const char *id = xs_list_get(v, 0);
@@ -2105,7 +2105,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                         xs *anc = xs_list_new();
                         xs *des = xs_list_new();
                         xs_list *p;
-                        xs_str *v;
+                        const xs_str *v;
                         char pid[64];
 
                         /* build the [grand]parent list, moving up */
@@ -2159,7 +2159,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                             l = object_likes(xs_dict_get(msg, "id"));
 
                         xs_list *p = l;
-                        xs_str *v;
+                        const xs_str *v;
 
                         while (xs_list_iter(&p, &v)) {
                             xs *actor2 = NULL;
@@ -2267,7 +2267,7 @@ int mastoapi_get_handler(const xs_dict *req, const char *q_path,
                         int cnt = 40;
                         xs *tl = content_search(&snac1, q, 1, 0, cnt, 0, &to);
                         int c = 0;
-                        char *v;
+                        const char *v;
 
                         while (xs_list_next(tl, &v, &c) && --cnt) {
                             xs *post = NULL;
@@ -2433,7 +2433,7 @@ int mastoapi_post_handler(const xs_dict *req, const char *q_path,
                 }
 
                 xs_list *p = mi;
-                xs_str *v;
+                const xs_str *v;
 
                 while (xs_list_iter(&p, &v)) {
                     xs *l    = xs_list_new();
@@ -2783,7 +2783,7 @@ int mastoapi_post_handler(const xs_dict *req, const char *q_path,
                             choices = xs_dict_get(args, "choices");
 
                         if (xs_type(choices) == XSTYPE_LIST) {
-                            xs_str *v;
+                            const xs_str *v;
 
                             int c = 0;
                             while (xs_list_next(choices, &v, &c)) {
@@ -2855,7 +2855,7 @@ int mastoapi_post_handler(const xs_dict *req, const char *q_path,
                 if (strcmp(op, "accounts") == 0) {
                     const xs_list *accts = xs_dict_get(args, "account_ids[]");
                     int c = 0;
-                    char *v;
+                    const char *v;
 
                     while (xs_list_next(accts, &v, &c)) {
                         list_content(&snac, id, v, 1);
@@ -2934,7 +2934,7 @@ int mastoapi_delete_handler(const xs_dict *req, const char *q_path,
                     p = xs_list_get(l, -2);
                     const xs_list *accts = xs_dict_get(args, "account_ids[]");
                     int c = 0;
-                    char *v;
+                    const char *v;
 
                     while (xs_list_next(accts, &v, &c)) {
                         list_content(&snac, p, v, 2);
@@ -3083,7 +3083,7 @@ void mastoapi_purge(void)
     xs *spec   = xs_fmt("%s/app/" "*.json", srv_basedir);
     xs *files  = xs_glob(spec, 1, 0);
     xs_list *p = files;
-    xs_str *v;
+    const xs_str *v;
 
     time_t mt = time(NULL) - 3600;
 
diff --git a/upgrade.c b/upgrade.c
index 266a4be..847c62e 100644
--- a/upgrade.c
+++ b/upgrade.c
@@ -43,7 +43,8 @@ int snac_upgrade(xs_str **error)
         else
         if (f < 2.2) {
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
@@ -52,7 +53,8 @@ int snac_upgrade(xs_str **error)
                 if (user_open(&snac, v)) {
                     xs *spec = xs_fmt("%s/actors/" "*.json", snac.basedir);
                     xs *list = xs_glob(spec, 0, 0);
-                    char *g, *fn;
+                    char *g;
+                    const char *fn;
 
                     g = list;
                     while (xs_list_iter(&g, &fn)) {
@@ -77,14 +79,16 @@ int snac_upgrade(xs_str **error)
         else
         if (f < 2.3) {
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
                 snac snac;
 
                 if (user_open(&snac, v)) {
-                    char *p, *v;
+                    char *p;
+                    const char *v;
                     xs *dir = xs_fmt("%s/hidden", snac.basedir);
 
                     /* create the hidden directory */
@@ -109,7 +113,8 @@ int snac_upgrade(xs_str **error)
         else
         if (f < 2.4) {
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
@@ -132,7 +137,8 @@ int snac_upgrade(xs_str **error)
         if (f < 2.5) {
             /* upgrade followers */
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
@@ -141,7 +147,8 @@ int snac_upgrade(xs_str **error)
                 if (user_open(&snac, v)) {
                     xs *spec = xs_fmt("%s/followers/" "*.json", snac.basedir);
                     xs *dir  = xs_glob(spec, 0, 0);
-                    char *p, *v;
+                    char *p;
+                    const char *v;
 
                     p = dir;
                     while (xs_list_iter(&p, &v)) {
@@ -175,7 +182,8 @@ int snac_upgrade(xs_str **error)
         if (f < 2.6) {
             /* upgrade local/ to public/ */
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
@@ -184,7 +192,8 @@ int snac_upgrade(xs_str **error)
                 if (user_open(&snac, v)) {
                     xs *spec = xs_fmt("%s/local/" "*.json", snac.basedir);
                     xs *dir  = xs_glob(spec, 0, 0);
-                    char *p, *v;
+                    char *p;
+                    const char *v;
 
                     p = dir;
                     while (xs_list_iter(&p, &v)) {
@@ -206,7 +215,7 @@ int snac_upgrade(xs_str **error)
                             /* if it's from us, add to public */
                             if (xs_startswith(id, snac.actor)) {
                                 const xs_list *p;
-                                char *v;
+                                const char *v;
                                 int c;
 
                                 object_user_cache_add(&snac, id, "public");
@@ -241,7 +250,8 @@ int snac_upgrade(xs_str **error)
         if (f < 2.7) {
             /* upgrade timeline/ to private/ */
             xs *users = user_list();
-            char *p, *v;
+            char *p;
+            const char *v;
 
             p = users;
             while (xs_list_iter(&p, &v)) {
@@ -250,7 +260,8 @@ int snac_upgrade(xs_str **error)
                 if (user_open(&snac, v)) {
                     xs *spec = xs_fmt("%s/timeline/" "*.json", snac.basedir);
                     xs *dir  = xs_glob(spec, 0, 0);
-                    char *p, *v;
+                    char *p;
+                    const char *v;
 
                     p = dir;
                     while (xs_list_iter(&p, &v)) {
@@ -271,7 +282,7 @@ int snac_upgrade(xs_str **error)
 
                             {
                                 const xs_list *p;
-                                char *v;
+                                const char *v;
                                 int c = 0;
 
                                 object_user_cache_add(&snac, id, "private");
diff --git a/utils.c b/utils.c
index daaa583..0e8e3be 100644
--- a/utils.c
+++ b/utils.c
@@ -358,7 +358,7 @@ void rm_rf(const char *dir)
     xs *d = xs_str_cat(xs_dup(dir), "/" "*");
     xs *l = xs_glob(d, 0, 0);
     xs_list *p = l;
-    xs_str *v;
+    const xs_str *v;
 
     if (dbglevel >= 1)
         printf("Deleting directory %s\n", dir);
@@ -393,7 +393,7 @@ int deluser(snac *user)
     int ret = 0;
     xs *fwers = following_list(user);
     xs_list *p = fwers;
-    xs_str *v;
+    const xs_str *v;
 
     while (xs_list_iter(&p, &v)) {
         xs *object = NULL;
@@ -419,7 +419,7 @@ void verify_links(snac *user)
 /* verifies a user's links */
 {
     const xs_dict *p = xs_dict_get(user->config, "metadata");
-    char *k, *v;
+    const char *k, *v;
     int changed = 0;
 
     xs *headers = xs_dict_new();
@@ -449,7 +449,7 @@ void verify_links(snac *user)
         xs *ls = xs_regex_select(payload, "< *(a|link) +[^>]+>");
 
         xs_list *lp = ls;
-        char *ll;
+        const char *ll;
         int vfied = 0;
 
         while (!vfied && xs_list_iter(&lp, &ll)) {
@@ -463,7 +463,7 @@ void verify_links(snac *user)
             xs *href = NULL;
             int is_rel_me = 0;
             xs_list *pr = r;
-            char *ar;
+            const char *ar;
 
             while (xs_list_iter(&pr, &ar)) {
                 xs *nq = xs_dup(ar);
diff --git a/webfinger.c b/webfinger.c
index b1d85e9..c79fd44 100644
--- a/webfinger.c
+++ b/webfinger.c
@@ -96,7 +96,7 @@ int webfinger_request_signed(snac *snac, const char *qs, char **actor, char **us
         if (actor != NULL) {
             const xs_list *list = xs_dict_get(obj, "links");
             int c = 0;
-            char *v;
+            const char *v;
 
             while (xs_list_next(list, &v, &c)) {
                 if (xs_type(v) == XSTYPE_DICT) {
diff --git a/xs.h b/xs.h
index b46f0e1..f361830 100644
--- a/xs.h
+++ b/xs.h
@@ -94,8 +94,8 @@ xs_list *xs_list_new(void);
 xs_list *xs_list_append_m(xs_list *list, const char *mem, int dsz);
 xs_list *_xs_list_append(xs_list *list, const xs_val *vals[]);
 #define xs_list_append(list, ...) _xs_list_append(list, (const xs_val *[]){ __VA_ARGS__, NULL })
-int xs_list_iter(xs_list **list, xs_val **value);
-int xs_list_next(const xs_list *list, xs_val **value, int *ctxt);
+int xs_list_iter(xs_list **list, const xs_val **value);
+int xs_list_next(const xs_list *list, const xs_val **value, int *ctxt);
 int xs_list_len(const xs_list *list);
 const xs_val *xs_list_get(const xs_list *list, int num);
 xs_list *xs_list_del(xs_list *list, int num);
@@ -118,7 +118,7 @@ xs_keyval *xs_keyval_make(xs_keyval *keyval, const xs_str *key, const xs_val *va
 xs_dict *xs_dict_new(void);
 xs_dict *xs_dict_append(xs_dict *dict, const xs_str *key, const xs_val *value);
 xs_dict *xs_dict_prepend(xs_dict *dict, const xs_str *key, const xs_val *value);
-int xs_dict_next(const xs_dict *dict, xs_str **key, xs_val **value, int *ctxt);
+int xs_dict_next(const xs_dict *dict, const xs_str **key, const xs_val **value, int *ctxt);
 const xs_val *xs_dict_get_def(const xs_dict *dict, const xs_str *key, const xs_val *def);
 #define xs_dict_get(dict, key) xs_dict_get_def(dict, key, NULL)
 xs_dict *xs_dict_del(xs_dict *dict, const xs_str *key);
@@ -726,7 +726,7 @@ xs_list *_xs_list_append(xs_list *list, const xs_val *vals[])
 }
 
 
-int xs_list_iter(xs_list **list, xs_val **value)
+int xs_list_iter(xs_list **list, const xs_val **value)
 /* iterates a list value */
 {
     int goon = 1;
@@ -757,7 +757,7 @@ int xs_list_iter(xs_list **list, xs_val **value)
 }
 
 
-int xs_list_next(const xs_list *list, xs_val **value, int *ctxt)
+int xs_list_next(const xs_list *list, const xs_val **value, int *ctxt)
 /* iterates a list, with context */
 {
     if (xs_type(list) != XSTYPE_LIST)
@@ -765,7 +765,7 @@ int xs_list_next(const xs_list *list, xs_val **value, int *ctxt)
 
     int goon = 1;
 
-    char *p = (char *)list;
+    const char *p = list;
 
     /* skip the start of the list */
     if (*ctxt == 0)
@@ -800,7 +800,7 @@ int xs_list_len(const xs_list *list)
 
     int c = 0;
     xs_list *p = (xs_list *)list;
-    xs_val *v;
+    const xs_val *v;
 
     while (xs_list_iter(&p, &v))
         c++;
@@ -819,7 +819,7 @@ const xs_val *xs_list_get(const xs_list *list, int num)
 
     int c = 0;
     xs_list *p = (xs_list *)list;
-    xs_val *v;
+    const xs_val *v;
 
     while (xs_list_iter(&p, &v)) {
         if (c == num)
@@ -881,7 +881,7 @@ xs_list *xs_list_dequeue(xs_list *list, xs_val **data, int last)
     XS_ASSERT_TYPE(list, XSTYPE_LIST);
 
     xs_list *p = list;
-    xs_val *v  = NULL;
+    const xs_val *v = NULL;
 
     if (!last) {
         /* get the first */
@@ -910,7 +910,7 @@ int xs_list_in(const xs_list *list, const xs_val *val)
 
     int n = 0;
     xs_list *p = (xs_list *)list;
-    xs_val *v;
+    const xs_val *v;
     int sz = xs_size(val);
 
     while (xs_list_iter(&p, &v)) {
@@ -931,7 +931,7 @@ xs_str *xs_join(const xs_list *list, const char *sep)
 
     xs_str *s = NULL;
     xs_list *p = (xs_list *)list;
-    xs_val *v;
+    const xs_val *v;
     int c = 0;
     int offset = 0;
     int ssz = strlen(sep);
@@ -1087,7 +1087,7 @@ xs_dict *xs_dict_prepend(xs_dict *dict, const xs_str *key, const xs_val *value)
 }
 
 
-int xs_dict_next(const xs_dict *dict, xs_str **key, xs_val **value, int *ctxt)
+int xs_dict_next(const xs_dict *dict, const xs_str **key, const xs_val **value, int *ctxt)
 /* iterates a dict, with context */
 {
     if (xs_type(dict) != XSTYPE_DICT)
@@ -1131,8 +1131,8 @@ const xs_val *xs_dict_get_def(const xs_dict *dict, const xs_str *key, const xs_v
     XS_ASSERT_TYPE(dict, XSTYPE_DICT);
     XS_ASSERT_TYPE(key, XSTYPE_STRING);
 
-    xs_str *k;
-    xs_val *v;
+    const xs_str *k;
+    const xs_val *v;
     int c = 0;
 
     while (xs_dict_next(dict, &k, &v, &c)) {
@@ -1150,14 +1150,14 @@ xs_dict *xs_dict_del(xs_dict *dict, const xs_str *key)
     XS_ASSERT_TYPE(dict, XSTYPE_DICT);
     XS_ASSERT_TYPE(key, XSTYPE_STRING);
 
-    xs_str *k;
-    xs_val *v;
+    const xs_str *k;
+    const xs_val *v;
     int c = 0;
 
     while (xs_dict_next(dict, &k, &v, &c)) {
         if (strcmp(k, key) == 0) {
             /* the address of the item is just behind the key */
-            char *i = k - 1;
+            char *i = (char *)k - 1;
 
             dict = xs_collapse(dict, i - dict, xs_size(i));
             break;
diff --git a/xs_curl.h b/xs_curl.h
index 2628d91..215db7f 100644
--- a/xs_curl.h
+++ b/xs_curl.h
@@ -93,8 +93,8 @@ xs_dict *xs_http_request(const char *method, const char *url,
     xs_dict *response;
     CURL *curl;
     struct curl_slist *list = NULL;
-    xs_str *k;
-    xs_val *v;
+    const xs_str *k;
+    const xs_val *v;
     long lstatus = 0;
     struct _payload_data pd;
 
diff --git a/xs_fcgi.h b/xs_fcgi.h
index 4727c5c..a1433a2 100644
--- a/xs_fcgi.h
+++ b/xs_fcgi.h
@@ -293,8 +293,8 @@ void xs_fcgi_response(FILE *f, int status, xs_dict *headers, xs_str *body, int b
     struct fcgi_record_header hdr = {0};
     struct fcgi_end_request ereq = {0};
     xs *out = xs_str_new(NULL);
-    xs_str *k;
-    xs_str *v;
+    const xs_str *k;
+    const xs_str *v;
 
     /* no previous id? it's an error */
     if (fcgi_id == -1)
diff --git a/xs_httpd.h b/xs_httpd.h
index 60933c8..4195b81 100644
--- a/xs_httpd.h
+++ b/xs_httpd.h
@@ -99,8 +99,8 @@ void xs_httpd_response(FILE *f, int status, xs_dict *headers, xs_str *body, int
 /* sends an httpd response */
 {
     xs *proto;
-    xs_str *k;
-    xs_val *v;
+    const xs_str *k;
+    const xs_val *v;
 
     proto = xs_fmt("HTTP/1.1 %d %s", status, status / 100 == 2 ? "OK" : "ERROR");
     fprintf(f, "%s\r\n", proto);
diff --git a/xs_json.h b/xs_json.h
index 3a7742d..b65e825 100644
--- a/xs_json.h
+++ b/xs_json.h
@@ -76,7 +76,7 @@ static void _xs_json_dump(const xs_val *data, int level, int indent, FILE *f)
 {
     int c = 0;
     int ct = 0;
-    xs_val *v;
+    const xs_val *v;
 
     switch (xs_type(data)) {
     case XSTYPE_NULL:
@@ -116,7 +116,7 @@ static void _xs_json_dump(const xs_val *data, int level, int indent, FILE *f)
     case XSTYPE_DICT:
         fputc('{', f);
 
-        xs_str *k;
+        const xs_str *k;
 
         while (xs_dict_next(data, &k, &v, &ct)) {
             if (c != 0)
diff --git a/xs_regex.h b/xs_regex.h
index cb73a01..cdb2cf8 100644
--- a/xs_regex.h
+++ b/xs_regex.h
@@ -64,7 +64,7 @@ xs_list *xs_regex_select_n(const char *str, const char *rx, int count)
 {
     xs_list *list = xs_list_new();
     xs *split = NULL;
-    xs_val *v;
+    const xs_val *v;
     int n = 0;
     int c = 0;
 
@@ -89,7 +89,7 @@ xs_list *xs_regex_replace_in(xs_str *str, const char *rx, const char *rep, int c
 {
     xs_str *s = xs_str_new(NULL);
     xs *split = xs_regex_split_n(str, rx, count);
-    xs_val *v;
+    const xs_val *v;
     int n = 0;
     int c = 0;
     int pholder = !!strchr(rep, '&');
diff --git a/xs_set.h b/xs_set.h
index b7eb091..12bac94 100644
--- a/xs_set.h
+++ b/xs_set.h
@@ -85,7 +85,8 @@ int xs_set_add(xs_set *s, const xs_val *data)
 {
     /* is it 'full'? */
     if (s->used >= s->elems / 2) {
-        char *p, *v;
+        char *p;
+        const xs_val *v;
 
         /* expand! */
         s->elems *= 2;
diff --git a/xs_url.h b/xs_url.h
index 69313b6..488a65f 100644
--- a/xs_url.h
+++ b/xs_url.h
@@ -52,7 +52,7 @@ xs_dict *xs_url_vars(const char *str)
         xs *args = xs_split(str, "&");
 
         xs_list *l;
-        xs_val *v;
+        const xs_val *v;
 
         l = args;
         while (xs_list_iter(&l, &v)) {
diff --git a/xs_version.h b/xs_version.h
index 9ecf9b8..9fb70ef 100644
--- a/xs_version.h
+++ b/xs_version.h
@@ -1 +1 @@
-/* 34850dcdec50b669a2c0bbe9f16f6d9c4b16eafd 2024-05-21T14:06:02+02:00 */
+/* 65265483c102909393287bfb173d1a7ae9c3be00 2024-05-23T09:57:20+02:00 */