diff --git a/projects/ujson/Dockerfile b/projects/ujson/Dockerfile
index fc9a8f166..9b43468da 100644
--- a/projects/ujson/Dockerfile
+++ b/projects/ujson/Dockerfile
@@ -20,7 +20,7 @@ RUN pip3 install hypothesis
 
 RUN git clone \
 	--depth 1 \
-	--branch master \
+	--branch main \
 	https://github.com/ultrajson/ultrajson.git
 
 WORKDIR ultrajson