diff --git a/src/server/wire.ts b/src/server/wire.ts
index 625462677..ca848007e 100644
--- a/src/server/wire.ts
+++ b/src/server/wire.ts
@@ -1,3 +1,5 @@
+import * as z from 'zod/v4';
+
 /// set this to true to see the tRPC and fetch requests made by the server
 export const SERVER_DEBUG_WIRE = false; //
 
@@ -56,6 +58,10 @@ export function safeErrorString(error: any): string | null {
     return `AggregateError: ${errors.join('; ')}`;
   }
 
+  // handle zod v4 errors
+  if (error instanceof z.ZodError)
+    return z.prettifyError(error);
+
   // descend into an 'error' object
   if (error.error)
     return safeErrorString(error.error);