diff --git a/progress.md b/progress.md
index 3958321..af565e5 100644
--- a/progress.md
+++ b/progress.md
@@ -22,7 +22,7 @@
  - [ ] 3.1 Integers
  - [ ] 3.2 Floating-Point Numbers
  - [ ] 3.3 Complex Numbers
- - [ ] 3.4 Booleans
+ - [x] 3.4 Booleans
  - [ ] 3.5 Strings
  - [ ] 3.6 Constants
 - [ ] Chapter 4: Composite Types