diff --git a/I. The Graph Data Structures.ipynb b/I. The Graph Data Structures.ipynb
index 779c754..1cea166 100644
--- a/I. The Graph Data Structures.ipynb	
+++ b/I. The Graph Data Structures.ipynb	
@@ -253,7 +253,7 @@
    },
    "outputs": [],
    "source": [
-    "for n in G.nodes_iter():\n",
+    "for n in G.nodes():\n",
     "    if type(n)== str:\n",
     "        print(n + ' is a string!')\n",
     "    else:\n",