diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 5137168d66..1cc16bfd31 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -920,6 +920,11 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, SDRequest req)
         sd->multi_blk_cnt = 0;
     }
 
+    if (sd_cmd_class[req.cmd] == 6 && FIELD_EX32(sd->ocr, OCR, CARD_CAPACITY)) {
+        /* Only Standard Capacity cards support class 6 commands */
+        return sd_illegal;
+    }
+
     switch (req.cmd) {
     /* Basic commands (Class 0 and Class 1) */
     case 0:	/* CMD0:   GO_IDLE_STATE */