diff --git a/src/calibre/db/tests/writing.py b/src/calibre/db/tests/writing.py
index a199da6b28..762517a294 100644
--- a/src/calibre/db/tests/writing.py
+++ b/src/calibre/db/tests/writing.py
@@ -297,6 +297,11 @@ class WritingTest(BaseTest):
         ae(sf('tags', {3: ('x', 'X')}), {3}, 'Failed when setting tag twice with different cases')
         ae(('x',), cache.field_for('tags', 3))
 
+        # Test setting of authors with | in their names (for legacy database
+        # format compatibility | is replaced by ,)
+        ae(sf('authors', {3: ('Some| Author',)}), {3})
+        ae(('Some, Author',), cache.field_for('authors', 3))
+
     # }}}
 
     def test_dirtied(self):  # {{{
diff --git a/src/calibre/db/write.py b/src/calibre/db/write.py
index fc8691aa42..ee81659984 100644
--- a/src/calibre/db/write.py
+++ b/src/calibre/db/write.py
@@ -156,7 +156,7 @@ def get_adapter(name, metadata):
     if name == 'author_sort':
         return lambda x: ans(x) or ''
     if name == 'authors':
-        return lambda x: ans(x) or (_('Unknown'),)
+        return lambda x: tuple(y.replace('|', ',') for y in ans(x)) or (_('Unknown'),)
     if name in {'timestamp', 'last_modified'}:
         return lambda x: ans(x) or UNDEFINED_DATE
     if name == 'series_index':