diff --git a/sdk/typescript/src/client.ts b/sdk/typescript/src/client.ts
index daa1b630..2e086401 100644
--- a/sdk/typescript/src/client.ts
+++ b/sdk/typescript/src/client.ts
@@ -112,7 +112,7 @@ export class PaygateClient {
   }
 
   private serializeRequestBody<TBody>(body: TBody | undefined): string | undefined {
-    if (body === undefined) return undefined;
+    if (body === undefined) return;
     try {
       return JSON.stringify(body);
     } catch (error) {
diff --git a/sdk/typescript/src/protocol/microai.ts b/sdk/typescript/src/protocol/microai.ts
index 93fa3d1b..b39b5885 100644
--- a/sdk/typescript/src/protocol/microai.ts
+++ b/sdk/typescript/src/protocol/microai.ts
@@ -128,7 +128,7 @@ export class MicroAIPaygateProtocol implements PaygateProtocolAdapter {
   }
 
   async getPayer(signer: PaymentSigner, ctx: PaymentContext): Promise<string | undefined> {
-    if (ctx.authorizationVersion !== 2) return undefined;
+    if (ctx.authorizationVersion !== 2) return;
     if (!signer.getAddress) {
       throw new PaygateSdkError(
         "payment_signature_failed",
diff --git a/web/src/lib/errors.ts b/web/src/lib/errors.ts
index 729f4e52..930f4139 100644
--- a/web/src/lib/errors.ts
+++ b/web/src/lib/errors.ts
@@ -96,7 +96,7 @@ function build(kind: ErrorKind, detail?: string): ClassifiedError {
 }
 
 function sanitizeDetail(raw: string | undefined): string | undefined {
-  if (!raw) return undefined;
+  if (!raw) return;
   try {
     const parsed = JSON.parse(raw);
     if (parsed.error && typeof parsed.error === "string") {