diff --git a/scripts/build/common.mjs b/scripts/build/common.mjs
index a792858f9..bcaf77362 100644
--- a/scripts/build/common.mjs
+++ b/scripts/build/common.mjs
@@ -36,7 +36,7 @@ const PackageJSON = JSON.parse(readFileSync(join(dirname(fileURLToPath(import.me
 
 export const VERSION = PackageJSON.version;
 // https://reproducible-builds.org/docs/source-date-epoch/
-export const BUILD_TIMESTAMP = Number(process.env.SOURCE_DATE_EPOCH) || Date.now();
+export const BUILD_TIMESTAMP = Number(process.env.SOURCE_DATE_EPOCH) * 1000 || Date.now();
 
 export const watch = process.argv.includes("--watch");
 export const IS_DEV = watch || process.argv.includes("--dev");