--- a/plugins/mod_admin_shell.lua	Sun May 15 16:12:34 2022 +0200
+++ b/plugins/mod_admin_shell.lua	Sun May 15 23:22:33 2022 +0200
@@ -50,12 +50,12 @@
 end
 
 local function pre(prefix, str, alt)
-	if (str or "") == "" then return alt or ""; end
+	if type(str) ~= "string" or str == "" then return alt or ""; end
 	return prefix .. str;
 end
 
 local function suf(str, suffix, alt)
-	if (str or "") == "" then return alt or ""; end
+	if type(str) ~= "string" or str == "" then return alt or ""; end
 	return str .. suffix;
 end