diff --git a/2021/README.md b/2021/README.md
index 7eb2f22..6465985 100644
--- a/2021/README.md
+++ b/2021/README.md
@@ -11,3 +11,4 @@
 | [Day 1](https://adventofcode.com/2021/day/1)   | [1.3404 ms](./solutions/day_01.py)             | [244.3283 us](./solutions/day_01.py)           |
 | [Day 2](https://adventofcode.com/2021/day/2)   | [995.6699 us](./solutions/day_02.py)           | [372.0404 us](./solutions/day_02.py)           |
 | [Day 3](https://adventofcode.com/2021/day/3)   | [5.5745 ms](./solutions/day_03.py)             | [919.8747 us](./solutions/day_03.py)           |
+| [Day 4](https://adventofcode.com/2021/day/4)   | [18.0422 ms](./solutions/day_04.py)            | [3.7518 ms](./solutions/day_04.py)             |