diff --git a/cores/arduino/USB/USBCore.cpp b/cores/arduino/USB/USBCore.cpp
index d27502c91c22593792692dbfb16a4a35a87ea709..bd815d367e9a3d35a5c455cd351e32d32b7f2bc3 100644
--- a/cores/arduino/USB/USBCore.cpp
+++ b/cores/arduino/USB/USBCore.cpp
@@ -427,7 +427,7 @@ void USBDeviceClass::initEP(uint32_t ep, uint32_t config)
 	}
 	else if (config == (USB_ENDPOINT_TYPE_BULK | USB_ENDPOINT_OUT(0)))
 	{
-		epHandlers[ep] = new DoubleBufferedEPOutHandler(usbd, ep, 64);
+		epHandlers[ep] = new DoubleBufferedEPOutHandler(usbd, ep, 256);
 	}
 	else if (config == (USB_ENDPOINT_TYPE_BULK | USB_ENDPOINT_IN(0)))
 	{