diff --git a/targets/ARCH/ETHERNET/USERSPACE/LIB/ethernet_lib.c b/targets/ARCH/ETHERNET/USERSPACE/LIB/ethernet_lib.c
index f5bc5ea767818fcba6fb48b31db26cd7a606b20d..e02e2573340a0ca99b865496871e5520e495eb4b 100644
--- a/targets/ARCH/ETHERNET/USERSPACE/LIB/ethernet_lib.c
+++ b/targets/ARCH/ETHERNET/USERSPACE/LIB/ethernet_lib.c
@@ -116,8 +116,8 @@ int trx_eth_start(openair0_device *device) {
     */
 
     /* adjust MTU wrt number of samples per packet */
-    /*if(ethernet_tune (device,MTU_SIZE,UDP_IF4p5_PRACH_SIZE_BYTES)!=0)  return -1;
-     */
+    if(ethernet_tune (device,MTU_SIZE,UDP_IF4p5_PRACH_SIZE_BYTES)!=0)  return -1;
+