diff --git a/2.5_exercise.ipynb b/2.5_exercise.ipynb
index 91e2114..6ad3ce6 100644
--- a/2.5_exercise.ipynb
+++ b/2.5_exercise.ipynb
@@ -265,7 +265,7 @@
     "<img src=\"images/fir_filter.png\" style=\"width:800px;\"/>\n",
     "\n",
     "`DspBlock`s use diplomatic interfaces from rocket.\n",
-    "[This site](https://www.lowrisc.org/docs/diplomacy/) has a good overview of the basic of diplomacy, but don't worry too much about how it's working for this example.\n",
+    "[This site](https://web.archive.org/web/20240610081349/https://lowrisc.org/docs/diplomacy/) has a good overview of the basic of diplomacy, but don't worry too much about how it's working for this example.\n",
     "Diplomacy really shines when you're connecting a lot of different blocks together to form a complex SoC.\n",
     "In this example, we're just making a single peripheral.\n",
     "The `StandaloneBlock` traits are mixed in to make diplomatic interfaces work as top-level IOs.\n",