diff --git a/src/lib/entityValidationSchemas.ts b/src/lib/entityValidationSchemas.ts
index 78086300..e4815198 100644
--- a/src/lib/entityValidationSchemas.ts
+++ b/src/lib/entityValidationSchemas.ts
@@ -104,7 +104,10 @@ export const companyValidationSchema = z.object({
   // Support both founded_date (preferred) and founded_year (legacy)
   founded_date: z.string().optional(),
   founded_date_precision: z.enum(['day', 'month', 'year']).optional(),
-  founded_year: z.coerce.number().int().min(1800).max(currentYear).optional().nullable(),
+  founded_year: z.preprocess(
+    (val) => val === '' || val === null || val === undefined ? undefined : val,
+    z.coerce.number().int().min(1800).max(currentYear).optional()
+  ).optional().nullable(),
   headquarters_location: z.string().max(200, 'Location must be less than 200 characters').optional(),
   website_url: z.string().optional().refine((val) => {
     if (!val || val === '') return true;