diff --git a/swh/indexer/metadata_dictionary.py b/swh/indexer/metadata_dictionary.py
--- a/swh/indexer/metadata_dictionary.py
+++ b/swh/indexer/metadata_dictionary.py
@@ -15,6 +15,7 @@
 
 import click
 import defusedxml.ElementTree
+import elementpath.exceptions
 import xmlschema
 
 from swh.indexer.codemeta import CROSSWALK_TABLE, SCHEMA_URI
@@ -423,7 +424,9 @@
     def translate(self, content):
         try:
             tree = defusedxml.ElementTree.fromstring(content)
-        except defusedxml.ElementTree.ParseError:
+            res = self.schema.to_dict(tree, validation='lax')
+        except (defusedxml.ElementTree.ParseError,
+                elementpath.exceptions.ElementPathError):
             self.log.warning('Error parsing XML from %s', self.log_suffix)
             return None
         except UnicodeDecodeError:
@@ -435,7 +438,6 @@
                              self.log_suffix)
             return None
 
-        res = self.schema.to_dict(tree, validation='lax')
         if res is None:
             d = {}
         else:
diff --git a/swh/indexer/tests/test_metadata.py b/swh/indexer/tests/test_metadata.py
--- a/swh/indexer/tests/test_metadata.py
+++ b/swh/indexer/tests/test_metadata.py
@@ -679,6 +679,24 @@
             self.assertEqual(cm.output, [expected_warning])
         self.assertEqual(result, None)
 
+        raw_content = b"""<?xml version="1.0" encoding="UTF-8"?>
+        <project xmlns="`ttp://maven.apache.org/POM/4.0.0">
+        </project>"""
+        with self.assertLogs('swh.indexer.metadata_dictionary',
+                             level='WARNING') as cm:
+            result = MAPPINGS["MavenMapping"]('foo').translate(raw_content)
+            self.assertEqual(cm.output, [expected_warning])
+        self.assertEqual(result, None)
+
+        raw_content = b"""<?xml version="1.0" encoding="UTF-8"?>
+        <project xmlns="http://}aven.apache.org/POM/4.0.0">
+        </project>"""
+        with self.assertLogs('swh.indexer.metadata_dictionary',
+                             level='WARNING') as cm:
+            result = MAPPINGS["MavenMapping"]('foo').translate(raw_content)
+            self.assertEqual(cm.output, [expected_warning])
+        self.assertEqual(result, None)
+
     def test_compute_metadata_maven_unknown_encoding(self):
         expected_warning = (
             'WARNING:swh.indexer.metadata_dictionary.MavenMapping:'