diff --git a/admin/__init__.py b/admin/__init__.py
index f5581eb22..891e1cdfe 100644
--- a/admin/__init__.py
+++ b/admin/__init__.py
@@ -40,12 +40,15 @@ def enabled_applications():
 
     :return: a list
     """
+    from modoboa.lib.dbutils import db_table_exists
+
     result = [("admin", "admin"), ("userprefs", "userprefs")]
-    try:
-        exts = Extension.objects.filter(enabled=True)
-        result += [(ext.name, ext.name) for ext in exts]
-    except DatabaseError:
-        pass
+    if db_table_exists("admin_extension"):
+        try:
+            exts = Extension.objects.filter(enabled=True)
+            result += [(ext.name, ext.name) for ext in exts]
+        except DatabaseError:
+            pass
     return sorted(result, key=lambda e: e[0])
 
 parameters.register_admin("DEFAULT_TOP_REDIRECTION", type="list", deflt="admin",
diff --git a/extensions/limits/migrations/0001_initial.py b/extensions/limits/migrations/0001_initial.py
index adf61f1ac..cc191e6e6 100644
--- a/extensions/limits/migrations/0001_initial.py
+++ b/extensions/limits/migrations/0001_initial.py
@@ -11,7 +11,7 @@ class Migration(SchemaMigration):
         # Adding model 'LimitsPool'
         db.create_table('limits_limitspool', (
             ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
-            ('user', self.gf('django.db.models.fields.related.OneToOneField')(to=orm['admin.User'], unique=True)),
+            ('user', self.gf('django.db.models.fields.related.OneToOneField')(to=orm['auth.User'], unique=True)),
         ))
         db.send_create_signal('limits', ['LimitsPool'])