--- a/spec/util_stanza_spec.lua	Thu Sep 13 17:28:50 2018 +0200
+++ b/spec/util_stanza_spec.lua	Thu Sep 13 16:35:48 2018 +0100
@@ -84,9 +84,20 @@
 	end);
 
 	describe("#iq()", function()
-		it("should work", function()
-			local i = st.iq();
-			assert.are.equal(i.name, "iq");
+		it("should create an iq stanza", function()
+			local i = st.iq({ id = "foo" });
+			assert.are.equal("iq", i.name);
+			assert.are.equal("foo", i.attr.id);
+		end);
+
+		it("should reject stanzas with no id", function ()
+			assert.has.error_match(function ()
+				local i = st.iq();
+			end, "id attribute");
+
+			assert.has.error_match(function ()
+				local i = st.iq({ foo = "bar" });
+			end, "id attribute");
 		end);
 	end);
 

--- a/util/stanza.lua	Thu Sep 13 17:28:50 2018 +0200
+++ b/util/stanza.lua	Thu Sep 13 16:35:48 2018 +0100
@@ -347,12 +347,6 @@
 	return error_type, condition or "undefined-condition", text;
 end
 
-local id = 0;
-local function new_id()
-	id = id + 1;
-	return "lx"..id;
-end
-
 local function preserialize(stanza)
 	local s = { name = stanza.name, attr = stanza.attr };
 	for _, child in ipairs(stanza) do
@@ -430,8 +424,10 @@
 	end
 end
 local function iq(attr)
-	if attr and not attr.id then attr.id = new_id(); end
-	return new_stanza("iq", attr or { id = new_id() });
+	if not (attr and attr.id) then
+		error("iq stanzas require an id attribute");
+	end
+	return new_stanza("iq", attr);
 end
 
 local function reply(orig)
@@ -502,7 +498,6 @@
 	stanza_mt = stanza_mt;
 	stanza = new_stanza;
 	is_stanza = is_stanza;
-	new_id = new_id;
 	preserialize = preserialize;
 	deserialize = deserialize;
 	clone = clone;