diff --git a/src/drivers/net/efi/nii.c b/src/drivers/net/efi/nii.c
index 8dd17e4b5..16e9e10df 100644
--- a/src/drivers/net/efi/nii.c
+++ b/src/drivers/net/efi/nii.c
@@ -30,6 +30,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <errno.h>
 #include <ipxe/netdevice.h>
 #include <ipxe/ethernet.h>
+#include <ipxe/if_ether.h>
 #include <ipxe/umalloc.h>
 #include <ipxe/efi/efi.h>
 #include <ipxe/efi/efi_driver.h>
@@ -998,6 +999,12 @@ static int nii_transmit ( struct net_device *netdev,
 		return 0;
 	}
 
+	/* Pad to minimum Ethernet length, to work around underlying
+	 * drivers that do not correctly handle frame padding
+	 * themselves.
+	 */
+	iob_pad ( iobuf, ETH_ZLEN );
+
 	/* Construct parameter block */
 	memset ( &cpb, 0, sizeof ( cpb ) );
 	cpb.FrameAddr = ( ( intptr_t ) iobuf->data );
diff --git a/src/drivers/net/efi/snpnet.c b/src/drivers/net/efi/snpnet.c
index c66aa7d28..b8bf963e9 100644
--- a/src/drivers/net/efi/snpnet.c
+++ b/src/drivers/net/efi/snpnet.c
@@ -26,6 +26,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/iobuf.h>
 #include <ipxe/netdevice.h>
 #include <ipxe/ethernet.h>
+#include <ipxe/if_ether.h>
 #include <ipxe/vsprintf.h>
 #include <ipxe/timer.h>
 #include <ipxe/efi/efi.h>
@@ -187,6 +188,12 @@ static int snpnet_transmit ( struct net_device *netdev,
 		return 0;
 	}
 
+	/* Pad to minimum Ethernet length, to work around underlying
+	 * drivers that do not correctly handle frame padding
+	 * themselves.
+	 */
+	iob_pad ( iobuf, ETH_ZLEN );
+
 	/* Transmit packet */
 	if ( ( efirc = snp->snp->Transmit ( snp->snp, 0, iob_len ( iobuf ),
 					    iobuf->data, NULL, NULL,