diff --git a/app.py b/app.py
index 6e54711..9aa75a6 100644
--- a/app.py
+++ b/app.py
@@ -11,7 +11,7 @@ match = re.search(r'(\d+)\.(\d+)', kernel_ver)
 cmv, csv = (int(match.group(1)), int(match.group(2))) if match else (0, 0)
 TFO = ""
 if cmv >= 3 and csv > 7:
-    tfo = "--tcp-fast-open"
+    TFO = "--tcp-fast-open"
 
 ARGS=os.getenv("ARGS","")