diff --git a/packages/server/src/utils/federationAuth.ts b/packages/server/src/utils/federationAuth.ts
index 71cd3fe5..c5f53f4f 100644
--- a/packages/server/src/utils/federationAuth.ts
+++ b/packages/server/src/utils/federationAuth.ts
@@ -96,7 +96,7 @@ export function parseFederationHeaders(
     const value = headers[name];
     if (value === undefined || value === null) return null;
     if (Array.isArray(value)) {
-      return value.length > 0 ? value[0] : null;
+      return value.length > 0 ? (value[0] ?? null) : null;
     }
     return value;
   };