diff --git a/swh/deposit/tests/api/test_checks.py b/swh/deposit/tests/api/test_checks.py
--- a/swh/deposit/tests/api/test_checks.py
+++ b/swh/deposit/tests/api/test_checks.py
@@ -286,6 +286,24 @@
_parameters3 = [
(textwrap.dedent(metadata_ko), expected_summary)
for (metadata_ko, expected_summary) in [
+ (
+ f"""\
+
+ some url
+
+ bar
+
+ no one
+ {PROVENANCE_XML}
+
+ """,
+ [
+ {
+ "summary": ".*Reason: a simple content element can't have child elements.*",
+ "fields": ["codemeta:name"],
+ },
+ ],
+ ),
(
f"""\
diff --git a/swh/deposit/xsd/codemeta.xsd b/swh/deposit/xsd/codemeta.xsd
--- a/swh/deposit/xsd/codemeta.xsd
+++ b/swh/deposit/xsd/codemeta.xsd
@@ -16,4 +16,6 @@
+
+