diff --git a/qinling/api/controllers/v1/function.py b/qinling/api/controllers/v1/function.py
index 2e5cf975..bce95f98 100644
--- a/qinling/api/controllers/v1/function.py
+++ b/qinling/api/controllers/v1/function.py
@@ -310,21 +310,27 @@ class FunctionsController(rest.RestController):
                     )
 
                 pre_source = pre_func.code['source']
-                pre_md5sum = pre_func.code['md5sum']
+                pre_md5sum = pre_func.code.get('md5sum')
+
                 if source and source != pre_source:
                     raise exc.InputException(
                         "The function code type can not be changed."
                     )
-                if md5sum and md5sum == pre_md5sum:
-                    raise exc.InputException(
-                        "The function code checksum is not changed."
-                    )
-                if source == constants.IMAGE_FUNCTION:
+
+                if pre_source == constants.IMAGE_FUNCTION:
                     raise exc.InputException(
                         "The image type function code can not be changed."
                     )
+
+                # Package type function. 'code' and 'entry' make sense only if
+                # 'package' is provided
                 if (pre_source == constants.PACKAGE_FUNCTION and
                         values.get('package') is not None):
+                    if md5sum and md5sum == pre_md5sum:
+                        raise exc.InputException(
+                            "The function code checksum is not changed."
+                        )
+
                     # Update the package data.
                     data = values['package'].file.read()
                     md5sum = self.storage_provider.store(
@@ -337,17 +343,23 @@ class FunctionsController(rest.RestController):
                         {"md5sum": md5sum, "source": pre_source}
                     )
                     values.pop('package')
+
+                # Swift type function
                 if pre_source == constants.SWIFT_FUNCTION:
                     swift_info = values['code'].get('swift', {})
                     self._check_swift(swift_info.get('container'),
                                       swift_info.get('object'))
 
-                # Delete allocated resources in orchestrator and etcd keys.
+                # Delete allocated resources in orchestrator and etcd.
                 self.engine_client.delete_function(id)
                 etcd_util.delete_function(id)
 
                 func_db = db_api.update_function(id, values)
 
+            # Delete function package if needed
+            if pre_md5sum:
+                self.storage_provider.delete(ctx.projectid, id, pre_md5sum)
+
         pecan.response.status = 200
         return resources.Function.from_dict(func_db.to_dict()).to_dict()
 
diff --git a/qinling/tests/unit/api/controllers/v1/test_function.py b/qinling/tests/unit/api/controllers/v1/test_function.py
index b984793e..1ece42d9 100644
--- a/qinling/tests/unit/api/controllers/v1/test_function.py
+++ b/qinling/tests/unit/api/controllers/v1/test_function.py
@@ -141,8 +141,10 @@ class TestFunctionController(base.APITest):
 
     @mock.patch('qinling.utils.etcd_util.delete_function')
     @mock.patch('qinling.storage.file_system.FileSystemStorage.store')
+    @mock.patch('qinling.storage.file_system.FileSystemStorage.delete')
     @mock.patch('qinling.rpc.EngineClient.delete_function')
-    def test_put_package(self, mock_delete_func, mock_store, mock_etcd_del):
+    def test_put_package(self, mock_delete_func, mock_delete, mock_store,
+                         mock_etcd_del):
         db_func = self.create_function(
             runtime_id=self.runtime_id, prefix=TEST_CASE_NAME
         )
@@ -158,8 +160,11 @@ class TestFunctionController(base.APITest):
         self.assertEqual(200, resp.status_int)
         self.assertEqual(1, mock_store.call_count)
         self.assertEqual('fake_md5_changed', resp.json['code'].get('md5sum'))
+
         mock_delete_func.assert_called_once_with(db_func.id)
         mock_etcd_del.assert_called_once_with(db_func.id)
+        mock_delete.assert_called_once_with(unit_base.DEFAULT_PROJECT_ID,
+                                            db_func.id, "fake_md5")
 
     def test_put_package_same_md5(self):
         db_func = self.create_function(