diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c
index 55714e08ca3addac4b880432456b06534c291283..0b93900b1dfa38225694a6f8166e64affeaee106 100644
--- a/drivers/net/can/dev/bittiming.c
+++ b/drivers/net/can/dev/bittiming.c
@@ -124,6 +124,9 @@ can_validate_bitrate(const struct net_device *dev, const struct can_bittiming *b
 			return 0;
 	}
 
+	NL_SET_ERR_MSG_FMT(extack, "bitrate %u bps not supported",
+			   bt->brp);
+
 	return -EINVAL;
 }