diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig
index 710d634d5c..c572c3c957 100644
--- a/fs/fat/Kconfig
+++ b/fs/fat/Kconfig
@@ -12,6 +12,18 @@ config FS_FAT
 
 if FS_FAT
 
+config FAT_COMPUTE_FSINFO
+	bool "FAT compute free space in FSINFO at mount time"
+	default n
+	---help---
+		Enables the computation of free clusters at mount time as suggested by the
+		white paper for FAT. The standard behavior of Nuttx is to trust the stored
+		value and only recompute it once required. This works if the file system
+		is never mounted to another OS. SD-cards which are mounted to Windows to
+		modify the content might report wrong space after reinserting it to Nuttx.
+		It is recommended to activate this setting if the "SD-Card" is swapped
+		between systems.
+
 config FAT_LCNAMES
 	bool "FAT upper/lower names"
 	default n
diff --git a/fs/fat/fs_fat32util.c b/fs/fat/fs_fat32util.c
index 7045068e85..d24d8fec08 100644
--- a/fs/fat/fs_fat32util.c
+++ b/fs/fat/fs_fat32util.c
@@ -626,13 +626,23 @@ int fat_mount(struct fat_mountpt_s *fs, bool writeable)
 
   if (fs->fs_type == FSTYPE_FAT32)
     {
-      ret = fat_computefreeclusters(fs);
+      ret = fat_checkfsinfo(fs);
       if (ret != OK)
         {
           goto errout_with_buffer;
         }
     }
 
+  /* Enforce computation of free clusters if configured */
+
+#ifdef CONFIG_FAT_COMPUTE_FSINFO
+  ret = fat_computefreeclusters(fs);
+  if (ret != OK)
+    {
+      goto errout_with_buffer;
+    }
+#endif
+
   /* We did it! */
 
   finfo("FAT%d:\n", fs->fs_type == 0 ? 12 : fs->fs_type == 1  ? 16 : 32);
@@ -2028,11 +2038,6 @@ int fat_updatefsinfo(struct fat_mountpt_s *fs)
 
 int fat_computefreeclusters(struct fat_mountpt_s *fs)
 {
-  if (fat_checkfsinfo(fs) != OK)
-    {
-      return -ENODEV;
-    }
-
   /* We have to count the number of free clusters */
 
   uint32_t nfreeclusters = 0;