diff --git a/lib/db.ts b/lib/db.ts
index b763018..9a87c73 100644
--- a/lib/db.ts
+++ b/lib/db.ts
@@ -13,10 +13,17 @@ mkdirSync(path.dirname(DB_PATH), { recursive: true });
 const db = new Database(DB_PATH);
 
 db.pragma('foreign_keys = ON');
-// If two processes are ever misconfigured onto the same file, WAL + a busy
-// timeout turns SQLITE_BUSY crashes into brief contention.
-db.pragma('journal_mode = WAL');
+// Timeout first: every later statement, including the journal switch below,
+// waits out a concurrent holder instead of failing with SQLITE_BUSY.
 db.pragma('busy_timeout = 5000');
+// WAL is best-effort. Switching journal mode needs the file to itself, and
+// `next build` imports this module from several workers while the live server
+// still holds the same file — a hard failure here fails the whole build.
+try {
+    db.pragma('journal_mode = WAL');
+} catch {
+    // Another connection holds the file; keep its journal mode.
+}
 
 db.exec(`
     CREATE TABLE IF NOT EXISTS instruments (
diff --git a/scripts/seed-settings.js b/scripts/seed-settings.js
index 46c7af0..abd0662 100644
--- a/scripts/seed-settings.js
+++ b/scripts/seed-settings.js
@@ -37,8 +37,12 @@ const DB_PATH = process.env.AUTOFIRMER_DB
 
 mkdirSync(path.dirname(DB_PATH), { recursive: true });
 const db = new Database(DB_PATH);
-db.pragma('journal_mode = WAL');
 db.pragma('busy_timeout = 5000');
+try {
+    db.pragma('journal_mode = WAL');
+} catch {
+    // Another connection holds the file; keep its journal mode.
+}
 
 // Mirrors the schema in lib/db.ts for every table a restore touches. The app
 // has usually never run at this point, so the tables may not exist yet; the