diff --git a/1. Message Structure/Lesson.ipynb b/1. Message Structure/Lesson.ipynb
index 71b685a..d707354 100644
--- a/1. Message Structure/Lesson.ipynb	
+++ b/1. Message Structure/Lesson.ipynb	
@@ -667,7 +667,7 @@
     "    assert stream.read(1) == b\"x\"\n",
     "    print(\"Test passed\")\n",
     "    \n",
-    "test_read_checksum()"
+    "test_read_payload()"
    ]
   },
   {