diff --git a/packages/trpc/server/document-router/schema.ts b/packages/trpc/server/document-router/schema.ts
index fceb6413f..899baa41f 100644
--- a/packages/trpc/server/document-router/schema.ts
+++ b/packages/trpc/server/document-router/schema.ts
@@ -77,7 +77,7 @@ export const ZSendDocumentMutationSchema = z.object({
     redirectUrl: z
       .string()
       .optional()
-      .refine((value) => value === undefined || URL_REGEX.test(value), {
+      .refine((value) => value === undefined || value === '' || URL_REGEX.test(value), {
         message: 'Please enter a valid URL',
       }),
   }),
diff --git a/packages/ui/primitives/document-flow/add-subject.types.ts b/packages/ui/primitives/document-flow/add-subject.types.ts
index fd4175368..c9027c2a3 100644
--- a/packages/ui/primitives/document-flow/add-subject.types.ts
+++ b/packages/ui/primitives/document-flow/add-subject.types.ts
@@ -13,7 +13,7 @@ export const ZAddSubjectFormSchema = z.object({
     redirectUrl: z
       .string()
       .optional()
-      .refine((value) => value === undefined || URL_REGEX.test(value), {
+      .refine((value) => value === undefined || value === '' || URL_REGEX.test(value), {
         message: 'Please enter a valid URL',
       }),
   }),