diff --git a/source/ch-instructor-guide/sec-instructor-intro.ptx b/source/ch-instructor-guide/sec-instructor-intro.ptx
index 1a5dc1c..31426d4 100644
--- a/source/ch-instructor-guide/sec-instructor-intro.ptx
+++ b/source/ch-instructor-guide/sec-instructor-intro.ptx
@@ -649,7 +649,7 @@
- [ |
+ [