diff --git a/01_the_machine_learning_landscape.ipynb b/01_the_machine_learning_landscape.ipynb
index 560bc53..6a080af 100644
--- a/01_the_machine_learning_landscape.ipynb
+++ b/01_the_machine_learning_landscape.ipynb
@@ -159,7 +159,7 @@
    "outputs": [],
    "source": [
     "full_country_stats = pd.merge(left=oecd_bli, right=gdp_per_capita, left_index=True, right_index=True)\n",
-    "full_country_stats.sort_values(by=\"GDP per capita\", inplace=\"True\")\n",
+    "full_country_stats.sort_values(by=\"GDP per capita\", inplace=True)\n",
     "full_country_stats"
    ]
   },