diff --git a/django/db/backends/ddl_references.py b/django/db/backends/ddl_references.py
index 44e49806f81..ba55de1df8b 100644
--- a/django/db/backends/ddl_references.py
+++ b/django/db/backends/ddl_references.py
@@ -83,10 +83,14 @@ class Columns(TableColumns):
 
     def __str__(self):
         def col_str(column, idx):
+            col = self.quote_name(column)
             try:
-                return self.quote_name(column) + self.col_suffixes[idx]
+                suffix = self.col_suffixes[idx]
+                if suffix:
+                    col = '{} {}'.format(col, suffix)
             except IndexError:
-                return self.quote_name(column)
+                pass
+            return col
 
         return ', '.join(col_str(column, idx) for idx, column in enumerate(self.columns))
 
@@ -114,7 +118,9 @@ class IndexColumns(Columns):
             # length as self.columns.
             col = '{} {}'.format(self.quote_name(column), self.opclasses[idx])
             try:
-                col = '{} {}'.format(col, self.col_suffixes[idx])
+                suffix = self.col_suffixes[idx]
+                if suffix:
+                    col = '{} {}'.format(col, suffix)
             except IndexError:
                 pass
             return col
diff --git a/tests/indexes/tests.py b/tests/indexes/tests.py
index 799146d6a8d..04ab036139f 100644
--- a/tests/indexes/tests.py
+++ b/tests/indexes/tests.py
@@ -83,6 +83,14 @@ class SchemaIndexesTests(TestCase):
             str(index.create_sql(Article, editor)),
         )
 
+    def test_descending_columns_list_sql(self):
+        index = Index(fields=['-headline'], name='whitespace_idx')
+        editor = connection.schema_editor()
+        self.assertIn(
+            '(%s DESC)' % editor.quote_name('headline'),
+            str(index.create_sql(Article, editor)),
+        )
+
 
 @skipIf(connection.vendor == 'postgresql', 'opclasses are PostgreSQL only')
 class SchemaIndexesNotPostgreSQLTests(TransactionTestCase):
@@ -231,6 +239,18 @@ class SchemaIndexesPostgreSQLTests(TransactionTestCase):
             cursor.execute(self.get_opclass_query % indexname)
             self.assertCountEqual(cursor.fetchall(), [('text_pattern_ops', indexname)])
 
+    def test_ops_class_columns_lists_sql(self):
+        index = Index(
+            fields=['headline'],
+            name='whitespace_idx',
+            opclasses=['text_pattern_ops'],
+        )
+        with connection.schema_editor() as editor:
+            self.assertIn(
+                '(%s text_pattern_ops)' % editor.quote_name('headline'),
+                str(index.create_sql(Article, editor)),
+            )
+
     def test_ops_class_descending_columns_list_sql(self):
         index = Index(
             fields=['-headline'],