diff --git a/buildkernel b/buildkernel
index fc6ba3e..c90342a 100755
--- a/buildkernel
+++ b/buildkernel
@@ -31,7 +31,7 @@ shopt -s nullglob
 # ********************** variables ********************* 
 PROGNAME="$(basename "${0}")"
 CONFFILE="/etc/${PROGNAME}.conf"
-VERSION="1.0.4"
+VERSION="1.0.5"
 DEFAULTEFIBOOTFILE="bootx64.efi"
 EFIBOOTFILE="${DEFAULTEFIBOOTFILE}"
 NEWVERSION="$(basename $(realpath "/usr/src/linux"))"
@@ -146,7 +146,7 @@ declare -i MOUNTEDONENTRY=0
 declare -i ARG_ASK=0 ARG_CLEAN=0 ARG_COPYFROMSTAGING=0 ARG_HELP=0
 declare -i ARG_STAGEONLY=0 ARG_UNMOUNTATEND=0 ARG_VERBOSE=0 ARG_VERSION=0
 declare -i ARG_POSTCLEAR=0 ARG_MENUCONFIG=0 ARG_SNAPSHOTBACKUP=0
-declare -i ARG_EASYSETUP=0
+declare -i ARG_EASYSETUP=0 ARG_IS_NEW_KERNEL_AVAILABLE=0
 
 # ***************** various functions ****************** 
 cleanup_and_exit_with_code() {
@@ -1483,7 +1483,14 @@ kernel_build_pass_1() {
 }
 rebuild_external_modules_if_necessary() {
     show "Creating any necessary external modules (e.g., VirtualBox)..."
-    emerge ${VERBOSITYFLAG} @module-rebuild
+    if ! emerge ${VERBOSITYFLAG} --noreplace @module-rebuild; then
+        if MAKEOPTS="${MAKEOPTS-} -j1" emerge --resume; then
+            warning "emerge @module-rebuild completed successfully, but only by restricting"
+            warning "build parallelism"
+        else
+            die "Failed to complete emerge @module-rebuild due to error"
+        fi
+    fi
 }
 create_initramfs_using_genkernel() {
     show "Creating initramfs (uncompressed)..."
@@ -1748,6 +1755,10 @@ Options:
                         use this option after compiling a kernel with
                         --stage-only, to copy it to the EFI system partition
   -h, --help            show this help message and exit
+  -i, --is-new-kernel-available
+                        return with code 0 if the currently-running kernel has
+                        a different version from that built in the staging area
+                        (at /boot), or 1 otherwise
   -m, --menuconfig      show kernel configuration GUI, even if non-interactive
   -p, --postclear       clear genkernel temporary files and caches after run
   -s, --stage-only      prepare kernel in /boot as usual, but do not copy 
@@ -1795,12 +1806,25 @@ snapshot_kernel_on_efi_partition() {
     backup_prior_config_if_present "${TIMESTAMP_PREFIX}"
     finalize_efi_partition_and_unmount_if_desired
 }
+exit_zero_if_new_kernel_available() {
+    # simple test - is the currently running kernel the same as the one
+    # present in the staging area?
+    # exit with code 0 if it is not (i.e., a new kernel IS available), or 1
+    # if it is
+    if [[ "${CURRENTVERSION}" != "${NEWVERSION}" && \
+        (-s "${BOOTDIR}/${VMLINUZNAME}" || -s "${BOOTDIR}/${VMLINUZNAME}${SIGNEDSUFFIX}")]]; then
+        cleanup_and_exit_with_code 0
+    else
+        # up to date, or no new kernel available, so th
+        cleanup_and_exit_with_code 1
+    fi
+}
 process_command_line_options() {
     local TEMP
     declare -i RC
     set +e
         # error trapping off, as we want to handle errors
-        TEMP="$(getopt -o abcefhmpsuvV --long ask,snapshot-backup,clean,easy-setup,copy-from-staging,help,menuconfig,postclear,stage-only,verbose,unmount-at-end,version -n "${PROGNAME}" -- "${@}")"
+        TEMP="$(getopt -o abcefhimpsuvV --long ask,snapshot-backup,clean,easy-setup,copy-from-staging,help,is-new-kernel-available,menuconfig,postclear,stage-only,verbose,unmount-at-end,version -n "${PROGNAME}" -- "${@}")"
         RC="${?}"
     set -e
     if ((RC!=0)); then
@@ -1817,6 +1841,7 @@ process_command_line_options() {
             -e|--easy-setup) ARG_EASYSETUP=1 ; shift ;;
             -f|--copy-from-staging) ARG_COPYFROMSTAGING=1 ; shift ;;
             -h|--help) ARG_HELP=1 ; shift ;;
+            -i|--is-new-kernel-available) ARG_IS_NEW_KERNEL_AVAILABLE=1 ; shift ;;
             -m|--menuconfig) ARG_MENUCONFIG=1 ; shift ;;
             -p|--postclear) ARG_POSTCLEAR=1 ; shift ;;
             -s|--stage-only) ARG_STAGEONLY=1 ; shift ;;
@@ -1854,6 +1879,8 @@ process_command_line_options() {
     if ((ARG_SNAPSHOTBACKUP==1)); then
         snapshot_kernel_on_efi_partition
         cleanup_and_exit_with_code 0
+    elif ((ARG_IS_NEW_KERNEL_AVAILABLE==1)); then
+        exit_zero_if_new_kernel_available
     fi
 }
 
diff --git a/buildkernel.8 b/buildkernel.8
index 4ce4b5d..db355c2 100644
--- a/buildkernel.8
+++ b/buildkernel.8
@@ -1,4 +1,4 @@
-.TH BUILDKERNEL 8 "Version 1.0.4: August 2014"
+.TH BUILDKERNEL 8 "Version 1.0.5: September 2014"
 .SH NAME
 buildkernel \- build secure boot kernel, save to EFI system partition
 .SH SYNOPSIS
@@ -121,6 +121,14 @@ is specified, only copying.
 .BR \-h ", " \-\-help
 Displays a short help screen, and exits.
 .TP
+.BR \-i ", " \-\-is\-new\-kernel\-available
+Returns an exit code of 0 if there is a kernel built in the staging area with
+the same version as the kernel tree pointed to by \fI/usr/src/linux\fR,
+\fBand\fR this is different to the version of the currently running kernel.
+(Note, this does not check whether the kernel has been copied to the EFI
+system partition.)
+Returns an exit code of 1 otherwise.
+.TP
 .BR \-m ", " \-\-menuconfig
 Specifies that the GUI-based kernel configuration step (\fBmake menuconfig\fR)
 should be performed at the appropriate stage in the process
@@ -191,6 +199,13 @@ The exit status is 0 if the kernel build completed successfully, and 1 otherwise
 \fBbuildkernel\fR currently executes the kernel build process as the root user.
 It would be a little more hygienic to build as a non-priveleged user, and then
 install as root.
+
+Note also that if have installed a package that uses external modules (such as
+VirtualBox), you will need to re-run \fBemerge @module-rebuild\fR once rebooted
+under your new kernel (as this set takes its version from the
+currently running kernel).
+A post-reboot run of \fBgenup\fR(8) will achieve this.
+
 .SH COPYRIGHT
 .nf
 Copyright \(co 2014 sakaki
diff --git a/buildkernel.conf.5 b/buildkernel.conf.5
index aab1be3..fb79903 100644
--- a/buildkernel.conf.5
+++ b/buildkernel.conf.5
@@ -1,4 +1,4 @@
-.TH BUILDKERNEL 5 "Version 1.0.4: August 2014"
+.TH BUILDKERNEL 5 "Version 1.0.5: September 2014"
 .SH NAME
 buildkernel.conf \- a configuration file for \fBbuildkernel\fR(8)
 .SH SYNOPSIS