diff --git a/firmware/common/disk.c b/firmware/common/disk.c
index c9676ed285..25c7330032 100644
--- a/firmware/common/disk.c
+++ b/firmware/common/disk.c
@@ -200,9 +200,8 @@ int disk_mount(int drive)
          volume != -1 && i < 4 && mounted < NUM_VOLUMES_PER_DRIVE;
          i++)
     {
-        if (memchr(fat_partition_types, pinfo[i].type,
-                   sizeof(fat_partition_types)) == NULL)
-            continue;  /* not an accepted partition type */
+        if (pinfo[i].type == 0 || pinfo[i].type == 5)
+            continue;  /* skip free/extended partitions */
 
     #ifdef MAX_LOG_SECTOR_SIZE
         for (int j = 1; j <= (MAX_LOG_SECTOR_SIZE/SECTOR_SIZE); j <<= 1)