diff --git a/src/util/geniso b/src/util/geniso
index d7ddbd2b..57e47471 100755
--- a/src/util/geniso
+++ b/src/util/geniso
@@ -22,8 +22,7 @@ then
 fi
 out=$1
 shift
-dir=bin/iso.dir
-mkdir -p $dir
+dir=`mktemp -d bin/iso.dir.XXXXXX`
 cfg=$dir/isolinux.cfg
 cp -p $isolinux_bin $dir
 cat > $cfg <<EOF
diff --git a/src/util/genliso b/src/util/genliso
index ac9924a6..aa517852 100755
--- a/src/util/genliso
+++ b/src/util/genliso
@@ -26,13 +26,12 @@ esac
 out=$1
 shift
 
-dir=bin/liso.dir
-mkdir -p $dir
+dir=`mktemp -d bin/liso.dir.XXXXXX`
 
 img=$dir/boot.img
 mformat -f 1440 -C -i $img ::
 
-cfg=bin/syslinux.cfg
+cfg=$dir/syslinux.cfg
 cat > $cfg <<EOF
 # These default options can be changed in the genliso script
 SAY gPXE ISO boot image generated by genliso
diff --git a/src/util/gensdsk b/src/util/gensdsk
index 68c339c2..787dfa25 100644
--- a/src/util/gensdsk
+++ b/src/util/gensdsk
@@ -24,11 +24,10 @@ Mtools\ version\ 3.9.9*|Mtools\ version\ 3.9.1[0-9]*|Mtools\ version\ 4.*)
 esac
 img=$1
 shift
-dir=bin/sdsk.dir
-mkdir -p $dir
+dir=`mktemp -d bin/sdsk.dir.XXXXXX`
 
 mformat -f 1440 -C -i $img ::
-cfg=bin/syslinux.cfg
+cfg=$dir/syslinux.cfg
 cat > $cfg <<EOF
 
 # These default options can be changed in the gensdsk script