diff --git a/registrar/source.py b/registrar/source.py
index 2ea8ad1040e333844d60272c729c1ac2575f28c7..5f17e0a05a1c647d0f39584e925967244de985f2 100644
--- a/registrar/source.py
+++ b/registrar/source.py
@@ -381,7 +381,7 @@ class HTTPSource(Source):
     def get_file(self, path: str, target_path: str):
         url = urljoin(self.endpoint_url, path)
         response = requests.get(url, allow_redirects=True)
-        with open(target_path, "w") as f:
+        with open(target_path, "wb") as f:
             f.write(response.content)
 
     @abstractmethod
diff --git a/requirements-dev.txt b/requirements-dev.txt
index d8fa1b7b77d9d489d8fe72d7c9dfa8372e295fc5..abc480988fefcefc9e9b79abf8a859518bfdc1ed 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -4,3 +4,4 @@ mypy==0.910
 
 types-redis
 types-PyYAML
+types-requests