diff --git a/radicale/__main__.py b/radicale/__main__.py
index 2f23636..bd09647 100644
--- a/radicale/__main__.py
+++ b/radicale/__main__.py
@@ -105,7 +105,7 @@ def run():
         if pid:
             sys.exit()
         elif config.get("server", "pid"):
-            open(config.get("server", "pid"), "w").write(str(pid))
+            open(config.get("server", "pid"), "w").write(str(os.getpid()))
         sys.stdout = sys.stderr = open(os.devnull, "w")
 
     # Register exit function