diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index eb1adc58ed65f0cd8d37f262917f69bc6d3f459d..2930468d58bd1c7bb0dec54b104b36aba70b546c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -317,6 +317,7 @@ For bigger changes, you'll want to create a unit test. Our tests are in the `tes
 We use `pytest` for unit testing. To run all unit tests, run the following in the root dir:
 
 ```bash
+pip install -r data_requirements.txt
 pytest tests
 ```
 
diff --git a/setup.py b/setup.py
index 55efe8c78c97b47f36c44f32010f35e97481bf1c..2ae733c552e0a274ccc5171d86481625644d9b32 100644
--- a/setup.py
+++ b/setup.py
@@ -29,6 +29,7 @@ install_requires = [
     "beautifulsoup4",  # hotfix for langchain 0.0.212 bug
     "nest_asyncio",
     "nltk",
+    "tree_sitter_languages",
 ]
 
 setup(