diff --git a/06_ensemble_learning_and_random_forests.ipynb b/06_ensemble_learning_and_random_forests.ipynb
index 25b63e4..ee574a4 100644
--- a/06_ensemble_learning_and_random_forests.ipynb
+++ b/06_ensemble_learning_and_random_forests.ipynb
@@ -498,7 +498,7 @@
     "        sample_weights /= sample_weights.sum()  # normalization step\n",
     "\n",
     "        plot_decision_boundary(svm_clf, X_train, y_train, alpha=0.4)\n",
-    "        plt.title(\"learning_rate = {}\".format(learning_rate))\n",
+    "        plt.title(f\"learning_rate = {learning_rate}\")\n",
     "    if subplot == 0:\n",
     "        plt.text(-0.75, -0.95, \"1\", fontsize=16)\n",
     "        plt.text(-1.05, -0.95, \"2\", fontsize=16)\n",