diff --git a/src/calibre/ebooks/metadata/opf3.py b/src/calibre/ebooks/metadata/opf3.py
index 7bfd51becc..6f41a58119 100644
--- a/src/calibre/ebooks/metadata/opf3.py
+++ b/src/calibre/ebooks/metadata/opf3.py
@@ -421,7 +421,7 @@ def set_authors(root, prefixes, refines, authors):
     for item in XPath('./opf:metadata/dc:creator')(root):
         props = properties_for_id_with_scheme(item.get('id'), prefixes, refines)
         opf_role = item.get(OPF('role'))
-        if (is_relators_role(props, 'aut')) or (opf_role and opf_role.lower() != 'aut'):
+        if (opf_role and opf_role.lower() != 'aut') or (props.get('role') and not is_relators_role(props, 'aut')):
             continue
         remove_element(item, refines)
     metadata = XPath('./opf:metadata')(root)[0]
@@ -457,7 +457,7 @@ def set_book_producers(root, prefixes, refines, producers):
     for item in XPath('./opf:metadata/dc:contributor')(root):
         props = properties_for_id_with_scheme(item.get('id'), prefixes, refines)
         opf_role = item.get(OPF('role'))
-        if (is_relators_role(props, 'bkp')) or (opf_role and opf_role.lower() != 'bkp'):
+        if (opf_role and opf_role.lower() != 'bkp') or (props.get('role') and not is_relators_role(props, 'bkp')):
             continue
         remove_element(item, refines)
     metadata = XPath('./opf:metadata')(root)[0]
diff --git a/src/calibre/ebooks/metadata/opf3_test.py b/src/calibre/ebooks/metadata/opf3_test.py
index 853226cd85..0acaf592d3 100644
--- a/src/calibre/ebooks/metadata/opf3_test.py
+++ b/src/calibre/ebooks/metadata/opf3_test.py
@@ -141,6 +141,9 @@ class TestOPF3(unittest.TestCase):
         authors = [Author('x y', 'y, x'), Author('u i', None)]
         self.ae(authors, st(root, authors))
         self.ae(root.get('prefix'), 'calibre: %s' % CALIBRE_PREFIX)
+        root = self.get_opf('''<dc:creator>a  b</dc:creator><dc:creator opf:role="aut">c d</dc:creator>''')
+        self.ae([Author('c d', None)], rl(root))
+        self.ae(authors, st(root, authors))
     # }}}
 
     def test_book_producer(self):  # {{{
@@ -155,7 +158,7 @@ class TestOPF3(unittest.TestCase):
             self.ae(['c d'], rl(root))
         root = self.get_opf('''<dc:contributor>a  b</dc:contributor><dc:contributor opf:role="bkp">c d</dc:contributor>''')
         self.ae(['c d'], rl(root))
-        self.ae('12'.split(), st(root, '12'.split()))
+        self.ae(['12'], st(root, ['12']))
     # }}}
 
     def test_dates(self):  # {{{