diff --git a/_notebooks/2023-08-01-Mario-Platform.ipynb b/_notebooks/2023-08-01-Mario-Platform.ipynb
index 8126d60..2914e18 100644
--- a/_notebooks/2023-08-01-Mario-Platform.ipynb
+++ b/_notebooks/2023-08-01-Mario-Platform.ipynb
@@ -247,12 +247,12 @@
     "        }\n",
     "    }\n",
     "    if (\n",
-    "                player1.position.y + player1.height <= platform.position.y &&\n",
-    "                player1.position.y + player1.height + player1.velocity.y > platform.position.y &&\n",
-    "                player1.position.x + player1.width >= platform.position.x &&\n",
-    "                player1.position.x <= platform.position.x + platform.width\n",
+    "                player.position.y + player.height <= platform.position.y &&\n",
+    "                player.position.y + player.height + player.velocity.y > platform.position.y &&\n",
+    "                player.position.x + player.width >= platform.position.x &&\n",
+    "                player.position.x <= platform.position.x + platform.width\n",
     "            ) {\n",
-    "                player1.velocity.y = 0;\n",
+    "                player.velocity.y = 0;\n",
     "            }\n",
     "\n",
     "    function animate() {\n",