diff --git a/usr/share/rear/format/USB/default/300_format_usb_disk.sh b/usr/share/rear/format/USB/default/300_format_usb_disk.sh
index 0e0a2e080..fa6496b23 100644
--- a/usr/share/rear/format/USB/default/300_format_usb_disk.sh
+++ b/usr/share/rear/format/USB/default/300_format_usb_disk.sh
@@ -94,7 +94,13 @@ sleep 5
 
 if is_true "$EFI" ; then
     LogPrint "Creating vfat filesystem on EFI system partition on '${RAW_USB_DEVICE}1'"
-    if ! mkfs.vfat $v -F 16 -n REAR-EFI ${RAW_USB_DEVICE}1 >&2 ; then
+    # Make a FAT filesystem on the EFI system partition
+    # cf. https://github.com/rear/rear/issues/2575
+    # and output/ISO/Linux-i386/700_create_efibootimg.sh
+    # and output/RAWDISK/Linux-i386/280_create_bootable_disk_image.sh
+    # Let mkfs.vfat automatically select the FAT type based on the size.
+    # I.e. do not use a '-F 16' or '-F 32' option and hope for the best:
+    if ! mkfs.vfat $v -n REAR-EFI ${RAW_USB_DEVICE}1 >&2 ; then
         Error "Failed to create vfat filesystem on '${RAW_USB_DEVICE}1'"
     fi
     # create link for EFI partition in /dev/disk/by-label
diff --git a/usr/share/rear/output/ISO/Linux-i386/700_create_efibootimg.sh b/usr/share/rear/output/ISO/Linux-i386/700_create_efibootimg.sh
index 0eb5350f8..39bbebad8 100644
--- a/usr/share/rear/output/ISO/Linux-i386/700_create_efibootimg.sh
+++ b/usr/share/rear/output/ISO/Linux-i386/700_create_efibootimg.sh
@@ -13,13 +13,33 @@ StopIfError "Failed to determine disk usage of EFI virtual image content directo
 
 # prepare EFI virtual image aligned to 32MiB blocks:
 dd if=/dev/zero of=$TMP_DIR/efiboot.img count=$efi_img_sz bs=32M
-mkfs.vfat $v -F 16 $TMP_DIR/efiboot.img >&2
-mkdir -p $v $TMP_DIR/efi_virt >&2
-mount $v -o loop -t vfat -o fat=16 $TMP_DIR/efiboot.img $TMP_DIR/efi_virt >&2
 
-# copy files from staging directory
+# Make a FAT filesystem on the efiboot.img file and loop mount it
+# cf. https://github.com/rear/rear/issues/2575
+# See output/RAWDISK/Linux-i386/280_create_bootable_disk_image.sh
+# Having a small EFI System Partition (ESP) might introduce problems:
+# - The UEFI spec seems to require a FAT32 EFI System Partition (ESP).
+# - syslinux/Legacy BIOS fails to install on small FAT32 partitions with "syslinux: zero FAT sectors (FAT12/16)".
+# - Some firmwares fail to boot from small FAT32 partitions.
+# - Some firmwares fail to boot from FAT16 partitions.
+# See:
+# - http://www.rodsbooks.com/efi-bootloaders/principles.html
+# - http://lists.openembedded.org/pipermail/openembedded-core/2012-January/055999.html
+# Let mkfs.vfat automatically select the FAT type based on the size.
+# See what "man mkfs.vfat" reads for the '-F' option:
+#  "If nothing is specified, mkfs.fat will automatically select
+#   between 12, 16 and 32 bit, whatever fits better for the filesystem size"
+# I.e. do not use a '-F 16' or '-F 32' option and hope for the best:
+mkfs.vfat $v $TMP_DIR/efiboot.img
+mkdir -p $v $TMP_DIR/efi_virt
+# Do not specify '-o fat=16' or '-o fat=32' when loop mounting the efiboot.img FAT file
+# but rely on the automatic FAT type detection (see what "man 8 mount" reads for 'fat=...'):
+mount $v -o loop -t vfat $TMP_DIR/efiboot.img $TMP_DIR/efi_virt || Error "Failed to loop mount efiboot.img"
+
+# Copy files from staging directory into efiboot.img
 cp $v -r $TMP_DIR/mnt/. $TMP_DIR/efi_virt
 
-umount $v $TMP_DIR/efiboot.img >&2
-mv $v -f $TMP_DIR/efiboot.img $TMP_DIR/isofs/boot/efiboot.img >&2
-StopIfError "Could not move efiboot.img file"
+umount $v $TMP_DIR/efiboot.img
+
+# Move efiboot.img into ISO directory:
+mv $v -f $TMP_DIR/efiboot.img $TMP_DIR/isofs/boot/efiboot.img || Error "Failed to move efiboot.img to isofs/boot/efiboot.img"
diff --git a/usr/share/rear/output/ISO/Linux-ia64/200_mount_bootimg.sh b/usr/share/rear/output/ISO/Linux-ia64/200_mount_bootimg.sh
index b5f603ec5..716d7d383 100644
--- a/usr/share/rear/output/ISO/Linux-ia64/200_mount_bootimg.sh
+++ b/usr/share/rear/output/ISO/Linux-ia64/200_mount_bootimg.sh
@@ -1,6 +1,11 @@
 # 200_mount_bootimg.sh
 dd if=/dev/zero of=$TMP_DIR/boot.img count=64000 bs=1024
-# make sure we select FAT16 instead of FAT12 as size >30MB
-mkfs.vfat $v -F 16 $TMP_DIR/boot.img >&2
-mkdir -p $v $TMP_DIR/mnt >&2
-mount $v -o loop -t vfat -o fat=16 $TMP_DIR/boot.img $TMP_DIR/mnt >&2
+# Make a FAT filesystem on the boot.img file and loop mount it
+# cf. https://github.com/rear/rear/issues/2575
+# and output/ISO/Linux-i386/700_create_efibootimg.sh
+# and output/RAWDISK/Linux-i386/280_create_bootable_disk_image.sh
+# Let mkfs.vfat automatically select the FAT type based on the size.
+# I.e. do not use a '-F 16' or '-F 32' option and hope for the best:
+mkfs.vfat $v $TMP_DIR/boot.img
+mkdir -p $v $TMP_DIR/mnt
+mount $v -o loop -t vfat $TMP_DIR/boot.img $TMP_DIR/mnt || Error "Failed to loop mount boot.img"