diff --git a/src/add-ons/kernel/drivers/ports/usb_serial/ACM.cpp b/src/add-ons/kernel/drivers/ports/usb_serial/ACM.cpp
index 7530e5a437..352510fb28 100644
--- a/src/add-ons/kernel/drivers/ports/usb_serial/ACM.cpp
+++ b/src/add-ons/kernel/drivers/ports/usb_serial/ACM.cpp
@@ -87,6 +87,7 @@ ACMDevice::AddDevice(const usb_configuration_info *config)
 			|| descriptor->interface_class == USB_CDC_DATA_INTERFACE_CLASS)
 			&& interface->endpoint_count >= 1) {
 			SetControlPipe(interface->endpoint[0].handle);
+			SetInterruptBufferSize(interface->endpoint[0].descr->max_packet_size);
 		} else {
 			TRACE("Indicated command interface doesn't fit our needs!\n");
 			status = ENODEV;
@@ -99,15 +100,21 @@ ACMDevice::AddDevice(const usb_configuration_info *config)
 		usb_interface_descriptor *descriptor = interface->descr;
 		if (descriptor->interface_class == USB_CDC_DATA_INTERFACE_CLASS
 			&& interface->endpoint_count >= 2) {
-			if (!(interface->endpoint[0].descr->endpoint_address & USB_ENDPOINT_ADDR_DIR_IN))
+			if (!(interface->endpoint[0].descr->endpoint_address & USB_ENDPOINT_ADDR_DIR_IN)) {
+				SetWriteBufferSize(ROUNDUP(interface->endpoint[0].descr->max_packet_size, 16));
 				SetWritePipe(interface->endpoint[0].handle);
-			else
+			} else {
+				SetReadBufferSize(ROUNDUP(interface->endpoint[0].descr->max_packet_size, 16));
 				SetReadPipe(interface->endpoint[0].handle);
+			}
 
-			if (interface->endpoint[1].descr->endpoint_address & USB_ENDPOINT_ADDR_DIR_IN)
+			if (interface->endpoint[1].descr->endpoint_address & USB_ENDPOINT_ADDR_DIR_IN) {
+				SetReadBufferSize(ROUNDUP(interface->endpoint[1].descr->max_packet_size, 16));
 				SetReadPipe(interface->endpoint[1].handle);
-			else
+			} else {
+				SetWriteBufferSize(ROUNDUP(interface->endpoint[1].descr->max_packet_size, 16));
 				SetWritePipe(interface->endpoint[1].handle);
+			}
 		} else {
 			TRACE("Indicated data interface doesn't fit our needs!\n");
 			status = ENODEV;