diff --git a/Lib/distutils/extension.py b/Lib/distutils/extension.py
index f0021d0..1d3112b 100644
--- a/Lib/distutils/extension.py
+++ b/Lib/distutils/extension.py
@@ -104,6 +104,6 @@
         self.extra_objects = extra_objects or []
         self.extra_compile_args = extra_compile_args or []
         self.extra_link_args = extra_link_args or []
-        self.export_symbols = export_symbols
+        self.export_symbols = export_symbols or []
 
 # class Extension