diff --git a/fs/ext2/ext2.mk b/fs/ext2/ext2.mk
index 16e14777c3..0d5fc7f118 100644
--- a/fs/ext2/ext2.mk
+++ b/fs/ext2/ext2.mk
@@ -12,6 +12,7 @@ EXT2_LABEL := $(subst ",,$(BR2_TARGET_ROOTFS_EXT2_LABEL))
 EXT2_OPTS = \
 	-G $(BR2_TARGET_ROOTFS_EXT2_GEN) \
 	-R $(BR2_TARGET_ROOTFS_EXT2_REV) \
+	-B 1024 \
 	-b $(BR2_TARGET_ROOTFS_EXT2_BLOCKS) \
 	-i $(BR2_TARGET_ROOTFS_EXT2_INODES) \
 	-I $(BR2_TARGET_ROOTFS_EXT2_EXTRA_INODES) \
diff --git a/package/mke2img/mke2img b/package/mke2img/mke2img
index 266df483aa..399012a2be 100755
--- a/package/mke2img/mke2img
+++ b/package/mke2img/mke2img
@@ -19,9 +19,10 @@ main() {
     rev=1
     nb_extra_inodes=0
 
-    while getopts :hb:i:I:r:d:o:G:R:l:u: OPT; do
+    while getopts :hB:b:i:I:r:d:o:G:R:l:u: OPT; do
         case "${OPT}" in
         h)  help; exit 0;;
+        B)  block_size="${OPTARG}";;
         b)  nb_blocks=${OPTARG};;
         i)  nb_inodes=${OPTARG};;
         I)  nb_extra_inodes=${OPTARG};;
@@ -47,6 +48,11 @@ main() {
     if [ -z "${nb_blocks}" ]; then
         error "you must specify the size of the output image with '-b'\n"
     fi
+    case "${block_size}" in
+    1024|2048|4096) ;; # Sole valid values
+    '') error "you must specify the size of a block with -B\n";;
+    *)  error "invalid block size '%s' (valid: 1024. 2048, 4096)\n" "${block_size}";;
+    esac
     case "${gen}:${rev}" in
     2:0|2:1|3:1|4:1)
         ;;
@@ -91,7 +97,7 @@ main() {
     fi
 
     # Generate the filesystem
-    genext2fs_opts=( -z -b ${nb_blocks} -N ${nb_inodes} -d "${root_dir}" )
+    genext2fs_opts=( -z -B ${block_size} -b ${nb_blocks} -N ${nb_inodes} -d "${root_dir}" )
     if [ -n "${nb_res_blocks}" ]; then
         genext2fs_opts+=( -m ${nb_res_blocks} )
     fi