diff --git a/README.md b/README.md
index d76f2be..833bee0 100644
--- a/README.md
+++ b/README.md
@@ -7,4 +7,6 @@ https://docs.google.com/presentation/d/1gwOGjteJa6iiTY-ZiTWNrz4ZB0kfvfk-fOxZHSr8
 
 # Lecture 3 - advanced git
 https://docs.google.com/presentation/d/1CXQUwNrswupqUBoLAVo7drDy6TvLAvEF-E20a3vnwII/edit#slide=id.p
+# Lecture 4
+http://bit.do/csc207