diff --git a/clean b/clean
index 6e83d27a..175356e3 100755
--- a/clean
+++ b/clean
@@ -8,5 +8,5 @@ test $# -gt 0 && exit 0  # convenience: 'clean top-level' to leave subsidiary to
 rm -rf tools/enumerate tangle/tangle tangle/*_list */*.dSYM
 rm -rf browse_trace/browse_trace_bin browse_trace/*_list
 rm -rf tools/treeshake
-rm -rf tmp mu-linux.iso outfs initrd.fat mu-soso.iso
+rm -rf tmp_linux mu_linux.iso outfs initrd.fat mu_soso.iso
 ( cd kernel.soso  &&  make clean; )
diff --git a/gen_linux_iso b/gen_linux_iso
index c2c4499f..f6769ec9 100755
--- a/gen_linux_iso
+++ b/gen_linux_iso
@@ -23,9 +23,9 @@ mv a.elf init
 chmod +x init
 
 echo "=== constructing initramfs out of SubX binary"
-rm -rf tmp/isoimage
-mkdir -p tmp/isoimage/boot
-echo init | cpio -R root:root -H newc -o | xz -9 --check=none > tmp/isoimage/boot/rootfs.xz
+rm -rf tmp_linux/isoimage
+mkdir -p tmp_linux/isoimage/boot
+echo init | cpio -R root:root -H newc -o | xz -9 --check=none > tmp_linux/isoimage/boot/rootfs.xz
 
 if [ ! -d kernel.linux ]
 then
@@ -37,26 +37,26 @@ echo "=== building linux kernel"
 ( cd kernel.linux
   make bzImage -j $(grep ^processor /proc/cpuinfo | wc -l)
 )
-cp *.linux/arch/x86/boot/bzImage tmp/isoimage/boot/kernel.xz
+cp *.linux/arch/x86/boot/bzImage tmp_linux/isoimage/boot/kernel.xz
 
 echo "=== downloading syslinux"
-test -f tmp/syslinux-6.03.tar.xz  ||  wget https://kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.03.tar.xz -P tmp
+test -f tmp_linux/syslinux-6.03.tar.xz  ||  wget https://kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.03.tar.xz -P tmp_linux
 echo "=== unpacking syslinux"
-tar xf tmp/syslinux-*.tar.xz -C tmp
+tar xf tmp_linux/syslinux-*.tar.xz -C tmp_linux
 
-mkdir -p tmp/isoimage/boot/syslinux
+mkdir -p tmp_linux/isoimage/boot/syslinux
 cp syslinux.cfg \
-   tmp/syslinux-*/bios/core/isolinux.bin \
-   tmp/syslinux-*/bios/com32/elflink/ldlinux/ldlinux.c32 \
-   tmp/isoimage/boot/syslinux
+   tmp_linux/syslinux-*/bios/core/isolinux.bin \
+   tmp_linux/syslinux-*/bios/com32/elflink/ldlinux/ldlinux.c32 \
+   tmp_linux/isoimage/boot/syslinux
 
-echo "=== generating mu-linux.iso"
+echo "=== generating mu_linux.iso"
 # 'hybrid' ISO can also be used on non-optical media such as a disk or USB stick
 xorriso -as mkisofs \
-  -isohybrid-mbr tmp/syslinux-*/bios/mbr/isohdpfx.bin \
+  -isohybrid-mbr tmp_linux/syslinux-*/bios/mbr/isohdpfx.bin \
   -c boot/syslinux/boot.cat \
   -b boot/syslinux/isolinux.bin \
     -no-emul-boot \
     -boot-load-size 4 \
     -boot-info-table \
-  tmp/isoimage -o mu_linux.iso
+  tmp_linux/isoimage -o mu_linux.iso
diff --git a/gen_soso_iso b/gen_soso_iso
index 5dd2dec5..734bc7f5 100755
--- a/gen_soso_iso
+++ b/gen_soso_iso
@@ -36,7 +36,7 @@ echo "=== building soso kernel"
   make
 )
 
-echo "=== generating mu-soso.iso"
+echo "=== generating mu_soso.iso"
 mkdir -p outfs/boot/grub
 cp kernel.soso/grub.cfg outfs/boot/grub
 cp kernel.soso/kernel.bin outfs/boot/