diff --git a/libisofs/ecma119.c b/libisofs/ecma119.c
index cdee22a..0f35799 100644
--- a/libisofs/ecma119.c
+++ b/libisofs/ecma119.c
@@ -1698,7 +1698,7 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
         system_area = src->system_area_data;
         system_area_options = src->system_area_options;
     } else {
-        system_area_options = opts->system_area_options & 0xfc;
+        system_area_options = opts->system_area_options & 0xfffffffc;
     }
     sa_type = (system_area_options >> 2) & 0x3f;
     if (sa_type != 0 && sa_type != 3)
@@ -2910,7 +2910,7 @@ int iso_write_opts_set_system_area(IsoWriteOpts *opts, char data[32768],
         memcpy(opts->system_area_data, data, 32768);
     }
     if (!(flag & 4))
-        opts->system_area_options = options & 0xff;
+        opts->system_area_options = options & 0x3ff;
     return ISO_SUCCESS;
 }
 
diff --git a/libisofs/ecma119.h b/libisofs/ecma119.h
index 2c4b9aa..eb2768f 100644
--- a/libisofs/ecma119.h
+++ b/libisofs/ecma119.h
@@ -575,19 +575,27 @@ struct ecma119_image
      */
     char *system_area_data;
     /*
-     * bit0= Only with PC-BIOS DOS MBR
+     * bit0= Only with DOS MBR
      *       Make bytes 446 - 512 of the system area a partition
      *       table which reserves partition 1 from byte 63*512 to the
      *       end of the ISO image. Assumed are 63 secs/hed, 255 head/cyl.
      *       (GRUB protective msdos label.)
      *       This works with and without system_area_data.
-     * bit1= Only with PC-BIOS DOS MBR
+     * bit1= Only with DOS MBR
      *       Apply isohybrid MBR patching to the system area.
      *       This works only with system_area_data plus ISOLINUX boot image
      *       and only if not bit0 is set.
      * bit2-7= System area type
      *       0= DOS MBR
      *       1= MIPS Big Endian Volume Header
+     *       2= DEC Boot Block for MIPS Little Endian
+     *       3= SUN Disk Label for SUN SPARC
+     * bit8-9= Only with DOS MBR
+     *       Cylinder alignment mode eventually pads the image to make it
+     *       end at a cylinder boundary.
+     *       0 = auto (align if bit1)
+     *       1 = always align to cylinder boundary
+     *       2 = never align to cylinder boundary
      */
     int system_area_options;
 
diff --git a/libisofs/libisofs.h b/libisofs/libisofs.h
index e0a1b73..65c4c47 100644
--- a/libisofs/libisofs.h
+++ b/libisofs/libisofs.h
@@ -1959,7 +1959,13 @@ int iso_write_opts_set_fifo_size(IsoWriteOpts *opts, size_t fifo_size);
  *                 iso_write_opts_set_partition_img() for partition numbers 2
  *                 to 8.
  *                 This will overwrite the first 512 bytes of the submitted
- *                 data.
+ *        bit8-9= Only with System area type 0 = MBR
+ *                @since 1.0.4
+ *                Cylinder alignment mode eventually pads the image to make it
+ *                end at a cylinder boundary.
+ *                0 = auto (align if bit1)
+ *                1 = always align to cylinder boundary
+ *                2 = never align to cylinder boundary
  * @param flag
  *        bit0 = invalidate any attached system area data. Same as data == NULL
  *               (This re-activates eventually loaded image System Area data.
diff --git a/libisofs/system_area.c b/libisofs/system_area.c
index 396abe7..45d34fc 100644
--- a/libisofs/system_area.c
+++ b/libisofs/system_area.c
@@ -841,17 +841,20 @@ int try_sph(off_t imgsize, int secs_per_head, int *heads_per_cyl, int flag)
 
 int iso_align_isohybrid(Ecma119Image *t, int flag)
 {
-    int sa_type, ret;
+    int sa_type, ret, always_align;
     uint32_t img_blocks;
     off_t imgsize, cylsize = 0, frac;
 
     sa_type = (t->system_area_options >> 2) & 0x3f;
     if (sa_type != 0)
         return ISO_SUCCESS;
+    always_align = (t->system_area_options >> 8) & 3;
+    if (always_align >= 2)
+        return ISO_SUCCESS;
 
     img_blocks = t->curblock;
     imgsize = ((off_t) img_blocks) * (off_t) 2048;
-    if ((t->system_area_options & 3)
+    if (((t->system_area_options & 3) || always_align)
         && (off_t) (t->partition_heads_per_cyl * t->partition_secs_per_head
                     * 1024) * (off_t) 512 < imgsize) {
         /* Choose small values which can represent the image size */
@@ -875,7 +878,7 @@ int iso_align_isohybrid(Ecma119Image *t, int flag)
     }
 
     cylsize = 0;
-    if (sa_type == 0 && t->catalog != NULL &&
+    if (t->catalog != NULL &&
                (t->catalog->bootimages[0]->isolinux_options & 0x0a) == 0x02) {
         /* Check for isolinux image with magic number of 3.72 and produce
            an MBR from our built-in template. (Deprecated since 31 Mar 2010)
@@ -883,7 +886,7 @@ int iso_align_isohybrid(Ecma119Image *t, int flag)
         if (img_blocks >= 0x40000000)
             return ISO_SUCCESS;
         cylsize = 64 * 32 * 512;
-    } else if (sa_type == 0 && (t->system_area_options & 2)) {
+    } else if ((t->system_area_options & 2) || always_align) {
         /* Patch externally provided system area as isohybrid MBR */
         if (t->catalog == NULL || t->system_area_data == NULL) {
             /* isohybrid makes only sense together with ISOLINUX boot image