diff --git a/docs/lessons/seismograph.md b/docs/lessons/seismograph.md
index 0e936268..1860a0c3 100644
--- a/docs/lessons/seismograph.md
+++ b/docs/lessons/seismograph.md
@@ -9,7 +9,7 @@ Acceleration & Analog Read Pin
 ## Quick Links
 
 * [activity](/lessons/seismograph/activity)
-* [challenge](/lessons/seismograph/challenges)
+* [challenge](/lessons/seismograph/challenge)
 
 ## Prior learning/place of lesson in scheme of work