diff --git a/morss/crawler.py b/morss/crawler.py
index b7cd1e3..2026ce6 100644
--- a/morss/crawler.py
+++ b/morss/crawler.py
@@ -630,7 +630,10 @@ class BaseCache:
             return True
 
 
-import sqlite3 # isort:skip
+try:
+    import sqlite3 # isort:skip
+except ImportError:
+    pass
 
 
 class SQLiteCache(BaseCache):
@@ -667,7 +670,10 @@ class SQLiteCache(BaseCache):
             self.con.execute('INSERT INTO data VALUES (?,?,?,?,?,?) ON CONFLICT(url) DO UPDATE SET code=?, msg=?, headers=?, data=?, timestamp=?', (url,) + value + value)
 
 
-import pymysql.cursors # isort:skip
+try:
+    import pymysql.cursors # isort:skip
+except ImportError:
+    pass
 
 
 class MySQLCacheHandler(BaseCache):
diff --git a/setup.py b/setup.py
index 9b584ad..2c72ed4 100644
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,8 @@ setup(
     download_url = 'https://git.pictuga.com/pictuga/morss',
     license = 'AGPL v3',
     packages = [package_name],
-    install_requires = ['lxml', 'bs4', 'python-dateutil', 'chardet', 'pymysql'],
+    install_requires = ['lxml', 'bs4', 'python-dateutil', 'chardet'],
+    extras_require = {'full': ['pymysql']},
     package_data = {package_name: ['feedify.ini']},
     data_files = [
         ('share/' + package_name, ['README.md', 'LICENSE']),