diff --git a/README.MD b/README.MD
index f2a2b23..4962cba 100644
--- a/README.MD
+++ b/README.MD
@@ -18,8 +18,8 @@ Building
 
 Build dependencies:
   * A Unix-like operating system
-  * bash
   * coreutils
+  * rw (optional)
   * dosfstools
   * mtools
   * nasm
diff --git a/make.sh b/make.sh
index 1feb043..cc36597 100755
--- a/make.sh
+++ b/make.sh
@@ -1,13 +1,13 @@
-#!/bin/bash
+#!/bin/sh
 
 rm -f EttinOS.img
-if [[ ! -d "bin" ]]
+if [ ! -d "bin" ]
 then
     mkdir bin
 fi
 
 cd src/
-if [ "$1" == "-1440" ]
+if [ "$1" = "-1440" ]
     then nasm BOOT.ASM -d F1440 -f bin -o ../bin/BOOT.BIN
     else nasm BOOT.ASM -f bin -o ../bin/BOOT.BIN
 fi
@@ -15,11 +15,15 @@ nasm SYSTEM.ASM -f bin -o ../bin/SYSTEM.BIN
 nasm HELLO.ASM -f bin -o ../bin/HELLO.BIN
 
 cd ..
-if [ "$1" == "-1440" ]
+if [ "$1" = "-1440" ]
     then mkfs.fat -C EttinOS.img 1440
     else mkfs.fat -C EttinOS.img 360
 fi
-dd if=bin/BOOT.BIN of=EttinOS.img conv=notrunc bs=512 count=1
+
+if which rw > /dev/null 2>&1
+    then rw -i bin/BOOT.BIN -o EttinOS.img -b 512 -c 1x
+    else dd if=bin/BOOT.BIN of=EttinOS.img conv=notrunc bs=512 count=1
+fi
 mcopy -i EttinOS.img bin/SYSTEM.BIN ::
 mcopy -i EttinOS.img bin/HELLO.BIN ::
 mcopy -i EttinOS.img README.MD ::