diff --git a/tests/test_fastapi.sh b/tests/test_fastapi.sh
index ff5a3e3..26fcc21 100755
--- a/tests/test_fastapi.sh
+++ b/tests/test_fastapi.sh
@@ -9,7 +9,6 @@ latest_tag_commit=$(git rev-list --tags --max-count=1)
 latest_tag=$(git describe --tags "${latest_tag_commit}")
 git checkout "${latest_tag}"
 
-pip install -U flit
-flit install
+pip install .[all,dev,doc,test]
 
 ./scripts/test.sh