diff --git a/scripts/release.py b/scripts/release.py
index f04734d..af28975 100644
--- a/scripts/release.py
+++ b/scripts/release.py
@@ -170,6 +170,11 @@ def main(argv=None, *, run=subprocess.run, repo_root: Path | None = None) -> int
         return result
 
     def precheck():
+        allowed = {
+            b.strip()
+            for b in os.environ.get("RELEASE_BRANCHES", "main").split(",")
+            if b.strip()
+        }
         for r in (backend, webui):
             out = run(["git", "-C", str(r), "status", "--porcelain"], capture_output=True, text=True)
             if out.stdout.strip():
@@ -178,9 +183,9 @@ def main(argv=None, *, run=subprocess.run, repo_root: Path | None = None) -> int
                 ["git", "-C", str(r), "branch", "--show-current"],
                 capture_output=True,
                 text=True,
-            )
-            if branch.stdout.strip() != "main":
-                raise RuntimeError(f"{r} is not on main")
+            ).stdout.strip()
+            if branch not in allowed:
+                raise RuntimeError(f"{r} is on {branch}, not in RELEASE_BRANCHES {sorted(allowed)}")
 
     def tests():
         if args.skip_tests: