diff --git a/README.md b/README.md
index 28fa86e..4c86ca9 100644
--- a/README.md
+++ b/README.md
@@ -79,5 +79,6 @@ This is my assignment in that specialization. This repo only includes lab files,
         ├── C2_W4.pdf
         ├── C2_W4_Lab_1_basic_mirrored_strategy.ipynb
         ├── C2_W4_Lab_2_multi_GPU_mirrored_strategy.ipynb
-        └── C2_W4_Lab_3_using_TPU_strategy.ipynb
+        ├── C2_W4_Lab_3_using_TPU_strategy.ipynb
+        └── C2_W4_Lab_4_one_device_strategy.ipynb
 ```
diff --git a/tree.txt b/tree.txt
index 1aea77d..6c93652 100644
--- a/tree.txt
+++ b/tree.txt
@@ -64,5 +64,6 @@
         ├── C2_W4.pdf
         ├── C2_W4_Lab_1_basic_mirrored_strategy.ipynb
         ├── C2_W4_Lab_2_multi_GPU_mirrored_strategy.ipynb
-        └── C2_W4_Lab_3_using_TPU_strategy.ipynb
+        ├── C2_W4_Lab_3_using_TPU_strategy.ipynb
+        └── C2_W4_Lab_4_one_device_strategy.ipynb
 ```