diff --git a/AUTHORS b/AUTHORS
index cf632452c6..e62c079413 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -567,6 +567,7 @@ answer newbie questions, and generally made Django that much better:
     Michael Placentra II <someone@michaelplacentra2.net>
     Michael Radziej <mir@noris.de>
     Michael Schwarz <michi.schwarz@gmail.com>
+    Michael Sinov <sihaelov@gmail.com>
     Michael Thornhill <michael.thornhill@gmail.com>
     Michal Chruszcz <troll@pld-linux.org>
     michal@plovarna.cz
diff --git a/django/core/management/commands/inspectdb.py b/django/core/management/commands/inspectdb.py
index 31c4ae062b..c84ce14739 100644
--- a/django/core/management/commands/inspectdb.py
+++ b/django/core/management/commands/inspectdb.py
@@ -269,16 +269,24 @@ class Command(BaseCommand):
         to the given database table name.
         """
         unique_together = []
+        has_unsupported_constraint = False
         for params in constraints.values():
             if params['unique']:
                 columns = params['columns']
+                if None in columns:
+                    has_unsupported_constraint = True
+                columns = [x for x in columns if x is not None]
                 if len(columns) > 1:
                     unique_together.append(str(tuple(column_to_field_name[c] for c in columns)))
         managed_comment = "  # Created from a view. Don't remove." if is_view else ""
-        meta = ["",
-                "    class Meta:",
-                "        managed = False%s" % managed_comment,
-                "        db_table = '%s'" % table_name]
+        meta = ['']
+        if has_unsupported_constraint:
+            meta.append('    # A unique constraint could not be introspected.')
+        meta += [
+            '    class Meta:',
+            '        managed = False%s' % managed_comment,
+            '        db_table = %r' % table_name
+        ]
         if unique_together:
             tup = '(' + ', '.join(unique_together) + ',)'
             meta += ["        unique_together = %s" % tup]
diff --git a/tests/inspectdb/models.py b/tests/inspectdb/models.py
index 8c660658cd..20f6b5e940 100644
--- a/tests/inspectdb/models.py
+++ b/tests/inspectdb/models.py
@@ -17,6 +17,7 @@ class PeopleData(models.Model):
 
 class PeopleMoreData(models.Model):
     people_unique = models.ForeignKey(People, models.CASCADE, unique=True)
+    message = models.ForeignKey(Message, models.CASCADE, blank=True, null=True)
     license = models.CharField(max_length=255)
 
 
diff --git a/tests/inspectdb/tests.py b/tests/inspectdb/tests.py
index b6bbf0b2dd..e994b2cb74 100644
--- a/tests/inspectdb/tests.py
+++ b/tests/inspectdb/tests.py
@@ -7,6 +7,8 @@ from django.db import connection
 from django.db.backends.base.introspection import TableInfo
 from django.test import TestCase, TransactionTestCase, skipUnlessDBFeature
 
+from .models import PeopleMoreData
+
 
 def inspectdb_tables_only(table_name):
     """
@@ -21,6 +23,7 @@ def special_table_only(table_name):
 
 
 class InspectDBTestCase(TestCase):
+    unique_re = re.compile(r'.*unique_together = \((.+),\).*')
 
     def test_stealth_table_name_filter_option(self):
         out = StringIO()
@@ -212,8 +215,7 @@ class InspectDBTestCase(TestCase):
         call_command('inspectdb', 'inspectdb_uniquetogether', stdout=out)
         output = out.getvalue()
         self.assertIn("    unique_together = (('", output)
-        unique_re = re.compile(r'.*unique_together = \((.+),\).*')
-        unique_together_match = re.findall(unique_re, output)
+        unique_together_match = re.findall(self.unique_re, output)
         # There should be one unique_together tuple.
         self.assertEqual(len(unique_together_match), 1)
         fields = unique_together_match[0]
@@ -225,6 +227,28 @@ class InspectDBTestCase(TestCase):
         # are given an integer suffix.
         self.assertIn("('non_unique_column', 'non_unique_column_0')", fields)
 
+    @skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific SQL')
+    def test_unsupported_unique_together(self):
+        """Unsupported index types (COALESCE here) are skipped."""
+        with connection.cursor() as c:
+            c.execute(
+                'CREATE UNIQUE INDEX Findex ON %s '
+                '(id, people_unique_id, COALESCE(message_id, -1))' % PeopleMoreData._meta.db_table
+            )
+        try:
+            out = StringIO()
+            call_command(
+                'inspectdb',
+                table_name_filter=lambda tn: tn.startswith(PeopleMoreData._meta.db_table),
+                stdout=out,
+            )
+            output = out.getvalue()
+            self.assertIn('# A unique constraint could not be introspected.', output)
+            self.assertEqual(re.findall(self.unique_re, output), ["('id', 'people_unique')"])
+        finally:
+            with connection.cursor() as c:
+                c.execute('DROP INDEX Findex')
+
     @skipUnless(connection.vendor == 'sqlite',
                 "Only patched sqlite's DatabaseIntrospection.data_types_reverse for this test")
     def test_custom_fields(self):