diff --git a/src/api/info/_methods/vaultDetails.ts b/src/api/info/_methods/vaultDetails.ts
index 36d154da..7b971007 100644
--- a/src/api/info/_methods/vaultDetails.ts
+++ b/src/api/info/_methods/vaultDetails.ts
@@ -121,7 +121,7 @@ export type VaultDetailsResponse = {
   allowDeposits: boolean;
   /** Position closure policy on withdrawal. */
   alwaysCloseOnWithdraw: boolean;
-};
+} | null;
 
 // ============================================================
 // Execution Logic
diff --git a/tests/api/info/vaultDetails.test.ts b/tests/api/info/vaultDetails.test.ts
index a75bfd19..f1bd78be 100644
--- a/tests/api/info/vaultDetails.test.ts
+++ b/tests/api/info/vaultDetails.test.ts
@@ -19,6 +19,7 @@ runTest({
         vaultAddress: "0xa15099a30bbf2e68942d6f4c43d70d04faeab0a0",
         user: "0xe019d6167E7e324aEd003d94098496b6d986aB05",
       }, // relationship.type = parent, user present
+      { vaultAddress: "0x0000000000000000000000000000000000000001" }, // vault does not exist
     ];
 
     const data = await Promise.all(params.map((p) => client.vaultDetails(p)));