diff --git a/django/core/management/sql.py b/django/core/management/sql.py
index 93a76f1c18c..feb932f3300 100644
--- a/django/core/management/sql.py
+++ b/django/core/management/sql.py
@@ -151,12 +151,12 @@ def custom_sql_for_model(model, style, connection):
     output = []
 
     # Post-creation SQL should come before any initial SQL data is loaded.
-    # However, this should not be done for fields that are part of a a parent
-    # model (via model inheritance).
-    nm = opts.init_name_map()
-    post_sql_fields = [f for f in opts.local_fields if hasattr(f, 'post_create_sql')]
-    for f in post_sql_fields:
-        output.extend(f.post_create_sql(style, model._meta.db_table))
+    # However, this should not be done for models that are unmanaged or
+    # for fields that are part of a parent model (via model inheritance).
+    if opts.managed:
+        post_sql_fields = [f for f in opts.local_fields if hasattr(f, 'post_create_sql')]
+        for f in post_sql_fields:
+            output.extend(f.post_create_sql(style, model._meta.db_table))
 
     # Some backends can't execute more than one SQL statement at a time,
     # so split into separate statements.