diff --git a/sys/cam/cam_ccb.h b/sys/cam/cam_ccb.h
index 772de3921122..cf5daf653079 100644
--- a/sys/cam/cam_ccb.h
+++ b/sys/cam/cam_ccb.h
@@ -1046,14 +1046,41 @@ struct ccb_trans_settings_mmc {
 #define MMC_PM		(1 << 5)
 #define MMC_BT		(1 << 6)
 #define MMC_BM		(1 << 7)
+#define MMC_VCCQ        (1 << 8)
 	uint32_t ios_valid;
 /* The folowing is used only for GET_TRAN_SETTINGS */
 	uint32_t	host_ocr;
 	int host_f_min;
 	int host_f_max;
-#define MMC_CAP_4_BIT_DATA	(1 << 0) /* Can do 4-bit data transfers */
-#define MMC_CAP_8_BIT_DATA	(1 << 1) /* Can do 8-bit data transfers */
-#define MMC_CAP_HSPEED		(1 << 2) /* Can do High Speed transfers */
+/* Copied from sys/dev/mmc/bridge.h */
+#define	MMC_CAP_4_BIT_DATA	(1 <<  0) /* Can do 4-bit data transfers */
+#define	MMC_CAP_8_BIT_DATA	(1 <<  1) /* Can do 8-bit data transfers */
+#define	MMC_CAP_HSPEED		(1 <<  2) /* Can do High Speed transfers */
+#define	MMC_CAP_BOOT_NOACC	(1 <<  4) /* Cannot access boot partitions */
+#define	MMC_CAP_WAIT_WHILE_BUSY	(1 <<  5) /* Host waits for busy responses */
+#define	MMC_CAP_UHS_SDR12	(1 <<  6) /* Can do UHS SDR12 */
+#define	MMC_CAP_UHS_SDR25	(1 <<  7) /* Can do UHS SDR25 */
+#define	MMC_CAP_UHS_SDR50	(1 <<  8) /* Can do UHS SDR50 */
+#define	MMC_CAP_UHS_SDR104	(1 <<  9) /* Can do UHS SDR104 */
+#define	MMC_CAP_UHS_DDR50	(1 << 10) /* Can do UHS DDR50 */
+#define	MMC_CAP_MMC_DDR52_120	(1 << 11) /* Can do eMMC DDR52 at 1.2 V */
+#define	MMC_CAP_MMC_DDR52_180	(1 << 12) /* Can do eMMC DDR52 at 1.8 V */
+#define	MMC_CAP_MMC_DDR52	(MMC_CAP_MMC_DDR52_120 | MMC_CAP_MMC_DDR52_180)
+#define	MMC_CAP_MMC_HS200_120	(1 << 13) /* Can do eMMC HS200 at 1.2 V */
+#define	MMC_CAP_MMC_HS200_180	(1 << 14) /* Can do eMMC HS200 at 1.8 V */
+#define	MMC_CAP_MMC_HS200	(MMC_CAP_MMC_HS200_120| MMC_CAP_MMC_HS200_180)
+#define	MMC_CAP_MMC_HS400_120	(1 << 15) /* Can do eMMC HS400 at 1.2 V */
+#define	MMC_CAP_MMC_HS400_180	(1 << 16) /* Can do eMMC HS400 at 1.8 V */
+#define	MMC_CAP_MMC_HS400	(MMC_CAP_MMC_HS400_120 | MMC_CAP_MMC_HS400_180)
+#define	MMC_CAP_MMC_HSX00_120	(MMC_CAP_MMC_HS200_120 | MMC_CAP_MMC_HS400_120)
+#define	MMC_CAP_MMC_ENH_STROBE	(1 << 17) /* Can do eMMC Enhanced Strobe */
+#define	MMC_CAP_SIGNALING_120	(1 << 18) /* Can do signaling at 1.2 V */
+#define	MMC_CAP_SIGNALING_180	(1 << 19) /* Can do signaling at 1.8 V */
+#define	MMC_CAP_SIGNALING_330	(1 << 20) /* Can do signaling at 3.3 V */
+#define	MMC_CAP_DRIVER_TYPE_A	(1 << 21) /* Can do Driver Type A */
+#define	MMC_CAP_DRIVER_TYPE_C	(1 << 22) /* Can do Driver Type C */
+#define	MMC_CAP_DRIVER_TYPE_D	(1 << 23) /* Can do Driver Type D */
+
 	uint32_t host_caps;
 	uint32_t host_max_data;
 };
diff --git a/sys/cam/mmc/mmc_xpt.c b/sys/cam/mmc/mmc_xpt.c
index 6e39cffd13ff..ad3ea9d8633c 100644
--- a/sys/cam/mmc/mmc_xpt.c
+++ b/sys/cam/mmc/mmc_xpt.c
@@ -167,6 +167,7 @@ typedef struct {
 	union ccb	saved_ccb;
 	uint32_t	flags;
 #define PROBE_FLAG_ACMD_SENT	0x1 /* CMD55 is sent, card expects ACMD */
+#define PROBE_FLAG_HOST_CAN_DO_18V   0x2 /* Host can do 1.8V signaling */
 	uint8_t         acmd41_count; /* how many times ACMD41 has been issued */
 	struct cam_periph *periph;
 } mmcprobe_softc;
@@ -457,6 +458,9 @@ mmc_print_ident(struct mmc_params *ident_data)
 		sbuf_printf(sb, "%sSDIO", space ? " " : "");
 		space = true;
 	}
+	if (ident_data->card_features & CARD_FEATURE_18V) {
+		sbuf_printf(sb, "%s1.8-Signaling", space ? " " : "");
+	}
 	sbuf_printf(sb, ">\n");
 
 	if (ident_data->card_features & CARD_FEATURE_MEMORY)
@@ -636,6 +640,9 @@ mmcprobe_start(struct cam_periph *periph, union ccb *start_ccb)
 		init_standard_ccb(start_ccb, XPT_GET_TRAN_SETTINGS);
 		xpt_action(start_ccb);
 
+		uint32_t host_caps = cts->host_caps;
+		if (host_caps & MMC_CAP_SIGNALING_180)
+			softc->flags |= PROBE_FLAG_HOST_CAN_DO_18V;
 		uint32_t hv = mmc_highest_voltage(cts->host_ocr);
 		init_standard_ccb(start_ccb, XPT_SET_TRAN_SETTINGS);
 		cts->ios.vdd = hv;
@@ -1008,6 +1015,18 @@ mmcprobe_done(struct cam_periph *periph, union ccb *done_ccb)
 				CAM_DEBUG(done_ccb->ccb_h.path, CAM_DEBUG_PROBE,
 					  ("Card supports 1.8V signaling\n"));
 				mmcp->card_features |= CARD_FEATURE_18V;
+				if (softc->flags & PROBE_FLAG_HOST_CAN_DO_18V) {
+					CAM_DEBUG(done_ccb->ccb_h.path, CAM_DEBUG_PROBE,
+						  ("Host supports 1.8V signaling. Switch voltage!\n"));
+					done_ccb->ccb_h.func_code = XPT_SET_TRAN_SETTINGS;
+					done_ccb->ccb_h.flags = CAM_DIR_NONE;
+					done_ccb->ccb_h.retry_count = 0;
+					done_ccb->ccb_h.timeout = 100;
+					done_ccb->ccb_h.cbfcnp = NULL;
+					done_ccb->cts.proto_specific.mmc.ios.vccq = vccq_180;
+					done_ccb->cts.proto_specific.mmc.ios_valid = MMC_VCCQ;
+					xpt_action(done_ccb);
+				}
 			}
 		} else {
 			CAM_DEBUG(done_ccb->ccb_h.path, CAM_DEBUG_PROBE,