diff --git a/stack_orchestrator/deploy/webapp/util.py b/stack_orchestrator/deploy/webapp/util.py
index b6d019aa..ef98117b 100644
--- a/stack_orchestrator/deploy/webapp/util.py
+++ b/stack_orchestrator/deploy/webapp/util.py
@@ -207,9 +207,11 @@ def build_container_image(app_record, tag, extra_build_args=[]):
         print(f"Cloning repository {repo} to {clone_dir} ...")
         if ref:
             # TODO: Determing branch or hash, and use depth 1 if we can.
-            result = subprocess.run(["git", "clone", repo, clone_dir])
-            result.check_returncode()
-            subprocess.check_call(["git", "checkout", ref], cwd=clone_dir)
+            git_env = dict(os.environ.copy())
+            # Never prompt
+            git_env["GIT_TERMINAL_PROMPT"] = "0"
+            subprocess.check_call(["git", "clone", repo, clone_dir], env=git_env)
+            subprocess.check_call(["git", "checkout", ref], cwd=clone_dir, env=git_env)
         else:
             result = subprocess.run(["git", "clone", "--depth", "1", repo, clone_dir])
             result.check_returncode()