diff --git a/acceptance/bin/callserver.py b/acceptance/bin/callserver.py
index c06d78f3b5..48a389b310 100755
--- a/acceptance/bin/callserver.py
+++ b/acceptance/bin/callserver.py
@@ -8,7 +8,7 @@
 env = {}
 for key, value in os.environ.items():
     if len(value) > 1000:
-        sys.stderr.write(f"Dropping key={key} value len={len(value)}")
+        sys.stderr.write(f"Dropping key={key} value len={len(value)}\n")
         continue
     env[key] = value