diff --git a/prosodyctl b/prosodyctl
index 964285a..0fcf2a5 100755
--- a/prosodyctl
+++ b/prosodyctl
@@ -803,15 +803,17 @@ function commands.cert(arg)
 			return 1; -- TODO Should we create it?
 		end
 		local uid = pposix.getuid();
-		if uid ~= 0 and uid ~= cert_dir_attrs.uid then
-			show_warning("The directory "..cert_basedir.." is not owned by the current user, won't be able to write files to it");
+		local gid = pposix.getgid();
+		if uid ~= 0 and not (
+			(cert_dir_attrs.permissions:match("^.w.......$") and uid == cert_dir_attrs.uid) or
+			(cert_dir_attrs.permissions:match("^....w....$") and gid == cert_dir_attrs.gid) or
+			cert_dir_attrs.permissions:match("^.......w.$")
+		) then
+			show_warning("The directory "..cert_basedir.." is not writable by this user");
 			return 1;
 		elseif not cert_dir_attrs.permissions then -- COMPAT with LuaFilesystem < 1.6.2 (hey CentOS!)
 			show_message("Unable to check permissions on "..cert_basedir.." (LuaFilesystem 1.6.2+ required)");
 			show_message("Please confirm that Prosody (and only Prosody) can write to this directory)");
-		elseif cert_dir_attrs.permissions:match("^%.w..%-..%-.$") then
-			show_warning("The directory "..cert_basedir.." not only writable by its owner");
-			return 1;
 		end
 		local subcmd = table.remove(arg, 1);
 		if type(cert_commands[subcmd]) == "function" then