diff --git a/frog/pipe.py b/frog/pipe.py
index ea7574ce..034c21e6 100644
--- a/frog/pipe.py
+++ b/frog/pipe.py
@@ -36,7 +36,7 @@
 code = ""
 py_version = sys.version_info.major
 sys.stdout.write("ready\n")
-sys.stdout.flush
+sys.stdout.flush()
 while 1:
     line_raw = sys.stdin.readline()
     if not line_raw: