diff --git a/brut.apktool/apktool-lib/src/main/java/brut/androlib/res/AndrolibResources.java b/brut.apktool/apktool-lib/src/main/java/brut/androlib/res/AndrolibResources.java
index 161b122c..175166e9 100644
--- a/brut.apktool/apktool-lib/src/main/java/brut/androlib/res/AndrolibResources.java
+++ b/brut.apktool/apktool-lib/src/main/java/brut/androlib/res/AndrolibResources.java
@@ -773,9 +773,17 @@ final public class AndrolibResources {
 
         try {
             if (OSDetection.isMacOSX()) {
-                aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/macosx/aapt");
+                if (OSDetection.is64Bit()) {
+                    aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/macosx/64/aapt");
+                } else {
+                    aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/macosx/32/aapt");
+                }
             } else if (OSDetection.isUnix()) {
-                aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/linux/aapt");
+                if (OSDetection.is64Bit()) {
+                    aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/linux/64/aapt");
+                } else {
+                    aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/linux/32/aapt");
+                }
             } else if (OSDetection.isWindows()) {
                 aaptBinary = Jar.getResourceAsFile("/prebuilt/aapt/windows/aapt.exe");
             } else {
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/32/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/32/aapt
new file mode 100755
index 00000000..d9764cbf
Binary files /dev/null and b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/32/aapt differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/64/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/64/aapt
new file mode 100755
index 00000000..32f9f867
Binary files /dev/null and b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/64/aapt differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/aapt
deleted file mode 100755
index c45a583c..00000000
Binary files a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/linux/aapt and /dev/null differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/32/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/32/aapt
new file mode 100644
index 00000000..f7a02aa3
Binary files /dev/null and b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/32/aapt differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/64/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/64/aapt
new file mode 100755
index 00000000..2f7343af
Binary files /dev/null and b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/64/aapt differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/aapt b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/aapt
deleted file mode 100644
index a8133333..00000000
Binary files a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/macosx/aapt and /dev/null differ
diff --git a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/windows/aapt.exe b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/windows/aapt.exe
index 597541c1..7827c893 100755
Binary files a/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/windows/aapt.exe and b/brut.apktool/apktool-lib/src/main/resources/prebuilt/aapt/windows/aapt.exe differ
diff --git a/brut.j.util/src/main/java/brut/util/OSDetection.java b/brut.j.util/src/main/java/brut/util/OSDetection.java
index 787bffa8..1157c8d7 100644
--- a/brut.j.util/src/main/java/brut/util/OSDetection.java
+++ b/brut.j.util/src/main/java/brut/util/OSDetection.java
@@ -18,17 +18,22 @@ package brut.util;
 
 public class OSDetection {
     private static String OS = System.getProperty("os.name").toLowerCase();
+    private static String Bit = System.getProperty("sun.arch.data.model").toLowerCase();
 
     public static boolean isWindows() {
-        return (OS.indexOf("win") >= 0);
+        return (OS.contains("win"));
     }
 
     public static boolean isMacOSX() {
-        return (OS.indexOf("mac") >= 0);
+        return (OS.contains("mac"));
     }
 
     public static boolean isUnix() {
-        return (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.indexOf("aix") > 0 || (OS.indexOf("sunos") >= 0));
+        return (OS.contains("nix") || OS.contains("nux") || OS.contains("aix") || (OS.contains("sunos")));
+    }
+
+    public static boolean is64Bit() {
+        return Bit.equalsIgnoreCase("64");
     }
 
     public static String returnOS() {