diff --git a/sys/dev/mlx5/driver.h b/sys/dev/mlx5/driver.h
index bc9b929df9d..2734b95bdbc 100644
--- a/sys/dev/mlx5/driver.h
+++ b/sys/dev/mlx5/driver.h
@@ -144,6 +144,7 @@ enum {
 	MLX5_REG_PVLC		 = 0x500F,
 	MLX5_REG_PMPE		 = 0x5010,
 	MLX5_REG_PMAOS		 = 0x5012,
+	MLX5_REG_PBSR		 = 0x5038,
 	MLX5_REG_PCAM		 = 0x507f,
 	MLX5_REG_NODE_DESC	 = 0x6001,
 	MLX5_REG_HOST_ENDIANNESS = 0x7004,