diff --git a/module_citeq.lua b/module_citeq.lua
index 4d1a58e..2c97880 100644
--- a/module_citeq.lua
+++ b/module_citeq.lua
@@ -569,6 +569,14 @@ local function _cite_q (citeq_args)
 	citeq_args.wdl = nil
 	citeq_args.template = nil
 
+	-- QID as normal form; emit error if not ^Q%d+$ (e.g. a Wikidata URL)
+	local qid_form = mw.ustring.match(mw.text.trim(qid), "^Q%d+$") or nil
+	if qid_form then
+		qid = qid_form
+	else
+		cq_errors = cq_errors .. ' <span class="error" style="font-size:inherit"><code class="cs1-code">{{[[Template:Cite Q|Cite Q]]}}</code>: QID parameter must be supplied as "Q" followed by digits, e.g. <code class="cs1-code">Q12345</code> ([[Template:Cite Q#Error messages|help]])</span> '
+	end
+
 	-- if title supplied, flag to not read html title
 	local titleforced = (citeq_args.title ~= nil)