diff --git a/firmware/common/disk.c b/firmware/common/disk.c
index e681fb64e3..d409c68ee1 100644
--- a/firmware/common/disk.c
+++ b/firmware/common/disk.c
@@ -434,6 +434,11 @@ int disk_mount(int drive)
             }
 #endif /* MAX_VIRT_SECTOR_SIZE */
         }
+
+#if defined(MAX_VIRT_SECTOR_SIZE) && defined(MAX_PHYS_SECTOR_SIZE)
+        if (mounted)
+            ata_set_phys_sector_mult(disk_sector_multiplier[drive]);
+#endif
     }
 
     disk_writer_unlock();
diff --git a/firmware/drivers/ata-common.c b/firmware/drivers/ata-common.c
index 016c93967a..3a1cea2dca 100644
--- a/firmware/drivers/ata-common.c
+++ b/firmware/drivers/ata-common.c
@@ -238,6 +238,10 @@ static int ata_get_phys_sector_mult(void)
         /* Check if drive really needs emulation  - if we can access
            sector 1 then assume the drive supports "512e" and will handle
            it better than us, so ignore the large physical sectors.
+
+           The exception here is if the device is partitioned to use
+           larger-than-logical "virtual" sectors; in that case we will
+           use whichever one (ie physical/"virtual") is larger.
         */
         char throwaway[__MAX_VARIABLE_LOG_SECTOR];
         rc = ata_transfer_sectors(1, 1, &throwaway, false);
@@ -254,4 +258,15 @@ static int ata_get_phys_sector_mult(void)
     return 0;
 }
 
+void ata_set_phys_sector_mult(unsigned int mult)
+{
+    unsigned int max = MAX_PHYS_SECTOR_SIZE/log_sector_size;
+    /* virtual sector could be larger than pyhsical sector */
+    if (!mult || mult > max)
+        mult = max;
+    /* It needs to be at _least_ the size of the real multiplier */
+    if (mult > phys_sector_mult)
+        phys_sector_mult = mult;
+}
+
 #endif  /* MAX_PHYS_SECTOR_SIZE */
diff --git a/firmware/export/ata.h b/firmware/export/ata.h
index dfa73eebf5..f29c052be3 100644
--- a/firmware/export/ata.h
+++ b/firmware/export/ata.h
@@ -235,4 +235,8 @@ int ata_read_smart(struct ata_smart_values*);
 
 #define ATA_IDENTIFY_WORDS 256
 
+#ifdef MAX_PHYS_SECTOR_SIZE
+void ata_set_phys_sector_mult(unsigned int mult);
+#endif
+
 #endif /* __ATA_H__ */