diff --git a/ml4/2_5_1_Exercise.ipynb b/ml4/2_5_1_Exercise.ipynb
index 37f40f6..617e00f 100644
--- a/ml4/2_5_1_Exercise.ipynb
+++ b/ml4/2_5_1_Exercise.ipynb
@@ -217,7 +217,7 @@
    "source": [
     "## Optional. Optimizing an ML pipeline with a genetic algorithm\n",
     "\n",
-    "The library [TPOT](#References) optimizes ML pipelines and comes with a lot of (examples)[https://epistasislab.github.io/tpot/examples/] and even notebooks, for example for the [iris dataset](https://github.com/EpistasisLab/tpot/blob/master/tutorials/IRIS.ipynb).\n",
+    "The library [TPOT](#References) optimizes ML pipelines and comes with a lot of [examples](https://epistasislab.github.io/tpot/examples/) and even notebooks, for example for the [iris dataset](https://github.com/EpistasisLab/tpot/blob/master/tutorials/IRIS.ipynb).\n",
     "\n",
     "Your task is to apply TPOT to the intermediate challenge and write a short essay explaining:\n",
     "* what TPOT does (with your own words).\n",