diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 3c8537052..73f37e3ec 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -60,8 +60,9 @@
   // Use 'postCreateCommand' to run commands after the container is created.
   // "postCreateCommand": "go version",
 
-  // See https://www.kenmuse.com/blog/avoiding-dubious-ownership-in-dev-containers/
-  "postStartCommand": "git config --global --add safe.directory ${containerWorkspaceFolder}",
+  // See https://www.kenmuse.com/blog/avoiding-dubious-ownership-in-dev-containers/ for the safe.directory part
+  // The defaultBranch part is required for our deprecated integration tests.
+  "postStartCommand": "git config --global --add safe.directory ${containerWorkspaceFolder} && git config --global init.defaultBranch master",
 
   // Set `remoteUser` to `root` to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
   "remoteUser": "vscode"