diff --git a/django/db/backends/postgresql/base.py b/django/db/backends/postgresql/base.py
index 0dab19ba0d9..b7be7951fca 100644
--- a/django/db/backends/postgresql/base.py
+++ b/django/db/backends/postgresql/base.py
@@ -192,7 +192,7 @@ def get_sql_flush(style, tables, sequences):
                 sql.append("%s %s %s %s %s %s;" % \
                     (style.SQL_KEYWORD('ALTER'),
                     style.SQL_KEYWORD('SEQUENCE'),
-                    style.SQL_FIELD('%s_%s_seq' % (table_name, column_name)),
+                    style.SQL_FIELD(quote_name('%s_%s_seq' % (table_name, column_name))),
                     style.SQL_KEYWORD('RESTART'),
                     style.SQL_KEYWORD('WITH'),
                     style.SQL_FIELD('1')
@@ -203,7 +203,7 @@ def get_sql_flush(style, tables, sequences):
                 sql.append("%s %s %s %s %s %s;" % \
                     (style.SQL_KEYWORD('ALTER'),
                      style.SQL_KEYWORD('SEQUENCE'),
-                     style.SQL_FIELD('%s_id_seq' % table_name),
+                     style.SQL_FIELD(quote_name('%s_id_seq' % table_name)),
                      style.SQL_KEYWORD('RESTART'),
                      style.SQL_KEYWORD('WITH'),
                      style.SQL_FIELD('1')
diff --git a/django/db/backends/postgresql_psycopg2/base.py b/django/db/backends/postgresql_psycopg2/base.py
index 58e232df685..bc722261bb8 100644
--- a/django/db/backends/postgresql_psycopg2/base.py
+++ b/django/db/backends/postgresql_psycopg2/base.py
@@ -149,7 +149,7 @@ def get_sql_flush(style, tables, sequences):
                 sql.append("%s %s %s %s %s %s;" % \
                     (style.SQL_KEYWORD('ALTER'),
                      style.SQL_KEYWORD('SEQUENCE'),
-                     style.SQL_FIELD('%s_%s_seq' % (table_name, column_name)),
+                     style.SQL_FIELD(quote_name('%s_%s_seq' % (table_name, column_name))),
                      style.SQL_KEYWORD('RESTART'),
                      style.SQL_KEYWORD('WITH'),
                      style.SQL_FIELD('1')
@@ -160,7 +160,7 @@ def get_sql_flush(style, tables, sequences):
                 sql.append("%s %s %s %s %s %s;" % \
                     (style.SQL_KEYWORD('ALTER'),
                      style.SQL_KEYWORD('SEQUENCE'),
-                     style.SQL_FIELD('%s_id_seq' % table_name),
+                     style.SQL_FIELD(quote_name('%s_id_seq' % table_name)),
                      style.SQL_KEYWORD('RESTART'),
                      style.SQL_KEYWORD('WITH'),
                      style.SQL_FIELD('1')
diff --git a/tests/regressiontests/fixtures_regress/models.py b/tests/regressiontests/fixtures_regress/models.py
index f9d4d350450..dd407df3533 100644
--- a/tests/regressiontests/fixtures_regress/models.py
+++ b/tests/regressiontests/fixtures_regress/models.py
@@ -7,6 +7,13 @@ class Animal(models.Model):
     def __str__(self):
         return self.common_name    
 
+class Plant(models.Model):
+    name = models.CharField(maxlength=150)
+
+    class Meta:
+        # For testing when upper case letter in app name; regression for #4057
+        db_table = "Fixtures_regress_plant"
+
 __test__ = {'API_TESTS':"""
 >>> from django.core import management