diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c b/drivers/net/ethernet/intel/i40e/i40e_common.c
index 5c36a18a31be9a0382184945ed4cbf123bea04d0..111426ba5fbcef4d856efeed10dec6ee34e95ed1 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_common.c
@@ -328,9 +328,9 @@ void i40e_debug_aq(struct i40e_hw *hw, enum i40e_debug_mask mask, void *desc,
 			len = buf_len;
 		/* write the full 16-byte chunks */
 		if (hw->debug_mask & mask) {
-			char prefix[20];
+			char prefix[27];
 
-			snprintf(prefix, 20,
+			snprintf(prefix, sizeof(prefix),
 				 "i40e %02x:%02x.%x: \t0x",
 				 hw->bus.bus_id,
 				 hw->bus.device,
diff --git a/drivers/net/ethernet/intel/i40evf/i40e_common.c b/drivers/net/ethernet/intel/i40evf/i40e_common.c
index d69c2e44cd1a125890871465c72b00e4b7ea9d36..8d3a2bfe186af812115f9973598d0ac75cc4dc69 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_common.c
@@ -333,9 +333,9 @@ void i40evf_debug_aq(struct i40e_hw *hw, enum i40e_debug_mask mask, void *desc,
 			len = buf_len;
 		/* write the full 16-byte chunks */
 		if (hw->debug_mask & mask) {
-			char prefix[20];
+			char prefix[27];
 
-			snprintf(prefix, 20,
+			snprintf(prefix, sizeof(prefix),
 				 "i40evf %02x:%02x.%x: \t0x",
 				 hw->bus.bus_id,
 				 hw->bus.device,