diff --git a/sys/dev/mgb/if_mgb.h b/sys/dev/mgb/if_mgb.h
index fe7f03a8dd73..55e84a6793fa 100644
--- a/sys/dev/mgb/if_mgb.h
+++ b/sys/dev/mgb/if_mgb.h
@@ -178,8 +178,8 @@
 #define MGB_DESC_GET_FRAME_LEN(_desc)	\
 	(((_desc)->ctl & MGB_DESC_FRAME_LEN_MASK) >> 16)
 
-#define MGB_NEXT_RING_IDX(_idx)		(((_idx) == MGB_DMA_RING_SIZE - 1) ? 0 : ((_idx_) + 1))
-#define MGB_PREV_RING_IDX(_idx)		(((_idx) == 0) ? (MGB_DMA_RING_SIZE - 1) : ((_idx_) - 1))
+#define MGB_NEXT_RING_IDX(_idx)		(((_idx) == MGB_DMA_RING_SIZE - 1) ? 0 : ((_idx) + 1))
+#define MGB_PREV_RING_IDX(_idx)		(((_idx) == 0) ? (MGB_DMA_RING_SIZE - 1) : ((_idx) - 1))
 #define MGB_RING_SPACE(_sc)		\
 	((((_sc)->tx_ring_data.last_head - (_sc)->tx_ring_data.last_tail - 1) \
 	 + MGB_DMA_RING_SIZE ) % MGB_DMA_RING_SIZE )