diff --git a/week1/notebook.ipynb b/week1/notebook.ipynb
index ac7da981376d8bff760d0131f67ad00a4562da7d..8d53ff52972eb6933d4f84249d6864deaca65fcd 100644
--- a/week1/notebook.ipynb
+++ b/week1/notebook.ipynb
@@ -47,7 +47,7 @@
    "source": [
     "m = 1 # point mass\n",
     "g = 1 # magnitude of the gravitational field\n",
-    "l = 1 # length of the rod"
+    "L = 1 # length of the rod"
    ]
   },
   {