diff --git a/src/tutorials/advanced/custom-codecs.ipynb b/src/tutorials/advanced/custom-codecs.ipynb
index 1dc280f7..cfa78be8 100644
--- a/src/tutorials/advanced/custom-codecs.ipynb
+++ b/src/tutorials/advanced/custom-codecs.ipynb
@@ -113,7 +113,7 @@
     "@schema\n",
     "class Connectivity(dj.Manual):\n",
     "    definition = \"\"\"\n",
-    "    conn_id : int\n",
+    "    conn_id : uint16\n",
     "    ---\n",
     "    network : <graph>\n",
     "    \"\"\""
@@ -253,7 +253,7 @@
     "@schema\n",
     "class Unit(dj.Manual):\n",
     "    definition = \"\"\"\n",
-    "    unit_id : int\n",
+    "    unit_id : uint16\n",
     "    ---\n",
     "    spikes : <spike_train>\n",
     "    \"\"\"\n",
@@ -304,4 +304,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 5
-}
+}
\ No newline at end of file