diff --git a/drivers/can/can_mcan.c b/drivers/can/can_mcan.c
index 887f45091c9..9a7e3fdd85a 100644
--- a/drivers/can/can_mcan.c
+++ b/drivers/can/can_mcan.c
@@ -500,7 +500,7 @@ static void can_mcan_tc_event_handler(const struct device *dev)
 			return;
 		}
 
-		tx_idx = tx_event.mm.idx;
+		tx_idx = tx_event.mm;
 
 		/* Acknowledge TX event */
 		err = can_mcan_write_reg(dev, CAN_MCAN_TXEFA, event_idx);
@@ -817,7 +817,6 @@ int can_mcan_send(const struct device *dev, const struct can_frame *frame, k_tim
 #endif /* !CONFIG_CAN_FD_MODE */
 		.efc = 1U,
 	};
-	struct can_mcan_mm mm;
 	uint32_t put_idx;
 	uint32_t reg;
 	int err;
@@ -894,10 +893,7 @@ int can_mcan_send(const struct device *dev, const struct can_frame *frame, k_tim
 	k_mutex_lock(&data->tx_mtx, K_FOREVER);
 
 	put_idx = FIELD_GET(CAN_MCAN_TXFQS_TFQPI, reg);
-
-	mm.idx = put_idx;
-	mm.cnt = data->mm.cnt++;
-	tx_hdr.mm = mm;
+	tx_hdr.mm = put_idx;
 
 	if ((frame->flags & CAN_FRAME_IDE) != 0U) {
 		tx_hdr.ext_id = frame->id;
diff --git a/drivers/can/can_mcan.h b/drivers/can/can_mcan.h
index a9364580080..98ccc793347 100644
--- a/drivers/can/can_mcan.h
+++ b/drivers/can/can_mcan.h
@@ -607,11 +607,6 @@ struct can_mcan_rx_fifo {
 	};
 } __packed __aligned(4);
 
-struct can_mcan_mm {
-	uint8_t idx: 5;
-	uint8_t cnt: 3;
-} __packed;
-
 struct can_mcan_tx_buffer_hdr {
 	union {
 		struct {
@@ -632,7 +627,7 @@ struct can_mcan_tx_buffer_hdr {
 	uint8_t fdf: 1;  /* FD Format */
 	uint8_t res2: 1; /* Reserved */
 	uint8_t efc: 1;  /* Event FIFO control (Store Tx events) */
-	struct can_mcan_mm mm;	  /* Message marker */
+	uint8_t mm;      /* Message marker */
 } __packed __aligned(4);
 
 struct can_mcan_tx_buffer {
@@ -657,7 +652,7 @@ struct can_mcan_tx_event_fifo {
 	uint8_t brs: 1; /* Bit Rate Switch */
 	uint8_t fdf: 1; /* FD Format */
 	uint8_t et: 2;	/* Event type */
-	struct can_mcan_mm mm;	 /* Message marker */
+	uint8_t mm;	/* Message marker */
 } __packed __aligned(4);
 
 #define CAN_MCAN_FCE_DISABLE	0x0
@@ -730,7 +725,6 @@ struct can_mcan_data {
 	uint16_t ext_filt_fd_frame;
 	uint16_t ext_filt_rtr;
 	uint16_t ext_filt_rtr_mask;
-	struct can_mcan_mm mm;
 	bool started;
 #ifdef CONFIG_CAN_FD_MODE
 	bool fd;