diff --git a/degesch.c b/degesch.c
index f5c0def..c73475b 100644
--- a/degesch.c
+++ b/degesch.c
@@ -1350,14 +1350,15 @@ struct channel_user
 	LIST_HEADER (struct channel_user)
 
 	struct user *user;                  ///< Reference to user
-	struct str prefixes;                ///< Ordered @+... characters
+	char *prefixes;                     ///< Ordered @+... characters
 };
 
 static struct channel_user *
-channel_user_new (void)
+channel_user_new (struct user *user, const char *prefixes)
 {
 	struct channel_user *self = xcalloc (1, sizeof *self);
-	self->prefixes = str_make ();
+	self->user = user;
+	self->prefixes = xstrdup (prefixes);
 	return self;
 }
 
@@ -1365,7 +1366,7 @@ static void
 channel_user_destroy (struct channel_user *self)
 {
 	user_unref (self->user);
-	str_free (&self->prefixes);
+	free (self->prefixes);
 	free (self);
 }
 
@@ -4417,9 +4418,9 @@ irc_get_channel_user_prefix (struct server *s,
 	struct channel_user *channel_user, struct str *output)
 {
 	if (s->ctx->show_all_prefixes)
-		str_append (output, channel_user->prefixes.str);
-	else if (channel_user->prefixes.len)
-		str_append_c (output, channel_user->prefixes.str[0]);
+		str_append (output, channel_user->prefixes);
+	else if (channel_user->prefixes[0])
+		str_append_c (output, channel_user->prefixes[0]);
 }
 
 static bool
@@ -4438,9 +4439,7 @@ irc_channel_link_user (struct channel *channel, struct user *user,
 	user_channel->channel = channel;
 	LIST_PREPEND (user->channels, user_channel);
 
-	struct channel_user *channel_user = channel_user_new ();
-	channel_user->user = user;
-	str_append (&channel_user->prefixes, prefixes);
+	struct channel_user *channel_user = channel_user_new (user, prefixes);
 	LIST_PREPEND (channel->users, channel_user);
 	channel->users_len++;
 }
@@ -6172,23 +6171,22 @@ mode_processor_do_user (struct mode_processor *self)
 	hard_assert (mode && (size_t) (mode - all_modes) < strlen (all_prefixes));
 	char prefix = all_prefixes[mode - all_modes];
 
-	struct str *prefixes = &channel_user->prefixes;
-	const char *pos = strchr (prefixes->str, prefix);
+	char **prefixes = &channel_user->prefixes;
+	char *pos = strchr (*prefixes, prefix);
 	if (self->adding == !!pos)
 		return;
 
 	if (self->adding)
 	{
 		// Add the new mode prefix while retaining the right order
-		char *old_prefixes = str_steal (prefixes);
-		*prefixes = str_make ();
+		struct str buf = str_make ();
 		for (const char *p = all_prefixes; *p; p++)
-			if (*p == prefix || strchr (old_prefixes, *p))
-				str_append_c (prefixes, *p);
-		free (old_prefixes);
+			if (*p == prefix || strchr (*prefixes, *p))
+				str_append_c (&buf, *p);
+		cstr_set (prefixes, str_steal (&buf));
 	}
 	else
-		str_remove_slice (prefixes, pos - prefixes->str, 1);
+		memmove (pos, pos + 1, strlen (pos));
 }
 
 static void
@@ -7248,9 +7246,9 @@ channel_user_sort_entry_cmp (const void *entry_a, const void *entry_b)
 
 	// First order by the most significant channel user prefix
 	const char *prio_a = strchr (s->irc_chanuser_prefixes,
-		*a->channel_user->prefixes.str);
+		a->channel_user->prefixes[0]);
 	const char *prio_b = strchr (s->irc_chanuser_prefixes,
-		*b->channel_user->prefixes.str);
+		b->channel_user->prefixes[0]);
 
 	// Put unrecognized prefixes at the end of the list
 	if (prio_a || prio_b)
@@ -7314,11 +7312,8 @@ irc_sync_channel_user (struct server *s, struct channel *channel,
 
 	// If our idea of the user's modes disagrees with what the server's
 	// sent us (the most powerful modes differ), use the latter one
-	if (channel_user->prefixes.str[0] != prefixes[0])
-	{
-		str_reset (&channel_user->prefixes);
-		str_append (&channel_user->prefixes, prefixes);
-	}
+	if (channel_user->prefixes[0] != prefixes[0])
+		cstr_set (&channel_user->prefixes, xstrdup (prefixes));
 }
 
 static void
@@ -8595,7 +8590,7 @@ lua_channel_get_users (lua_State *L)
 		lua_createtable (L, 0, 2);
 		lua_weak_push (L, wrapper->plugin, iter->user, &lua_user_info);
 		lua_setfield (L, -2, "user");
-		lua_plugin_kv (L, "prefixes", iter->prefixes.str);
+		lua_plugin_kv (L, "prefixes", iter->prefixes);
 
 		lua_rawseti (L, -2, i++);
 	}