diff --git a/arch/arm/src/stm32/stm32_eth.c b/arch/arm/src/stm32/stm32_eth.c
index 7fa8cd7e8c..e9c38e0628 100644
--- a/arch/arm/src/stm32/stm32_eth.c
+++ b/arch/arm/src/stm32/stm32_eth.c
@@ -1134,7 +1134,7 @@ static int stm32_transmit(struct stm32_ethmac_s *priv)
 
       /* Set frame size */
 
-      DEBUGASSERT(priv->dev.d_len <= CONFIG_NET_ETH_PKTSIZE);
+      DEBUGASSERT(priv->dev.d_len <= CONFIG_STM32_ETH_BUFSIZE);
       txdesc->tdes1 = priv->dev.d_len;
 
       /* Set the Buffer1 address pointer */