diff --git a/src/com/froop/app/kegs/KegsMain.java b/src/com/froop/app/kegs/KegsMain.java
index 8ca0a89..8759047 100644
--- a/src/com/froop/app/kegs/KegsMain.java
+++ b/src/com/froop/app/kegs/KegsMain.java
@@ -53,11 +53,11 @@ public class KegsMain extends SherlockFragmentActivity implements KegsKeyboard.S
   private long mScreenSizeTime = 0;
 
   private boolean mPaused = false;
-  final ArrayDeque<Runnable> mResumeQueue = new ArrayDeque<Runnable>();
-  final Runnable mErrorFinish = new Runnable() { public void run() { finish(); } };
+  private final ArrayDeque<Runnable> mResumeQueue = new ArrayDeque<Runnable>();
+  private final Runnable mErrorFinish = new Runnable() { public void run() { finish(); } };
 
   private DiskLoader mDiskLoader = null;
-  private int mNextDriveNumber = 2;
+  private final DiskImage.DriveNumber mDriveNumber = new DiskImage.DriveNumber();
 
   private void withUIActive(final Runnable runnable) {
     if(!mPaused) {
@@ -153,12 +153,7 @@ public class KegsMain extends SherlockFragmentActivity implements KegsKeyboard.S
           getThread().allowPowerOn();
         } else if (image.action == DiskImage.SWAP) {
           if (image.isHardDrive()) {
-            // Probably not the right place for this.
-            image.updateDriveNumber(mNextDriveNumber);
-            mNextDriveNumber += 1;
-            if (mNextDriveNumber > 7) {
-              mNextDriveNumber = 2;
-            }
+            image.chooseDriveNumber(mDriveNumber);
           }
           getThread().getEventQueue().add(image.getDiskImageEvent());
         }
diff --git a/src/com/froop/app/kegs/diskimage/DiskImage.java b/src/com/froop/app/kegs/diskimage/DiskImage.java
index 844abd5..7e35c69 100644
--- a/src/com/froop/app/kegs/diskimage/DiskImage.java
+++ b/src/com/froop/app/kegs/diskimage/DiskImage.java
@@ -116,8 +116,12 @@ class DiskImage implements Comparable {
     }
   }
 
-  public void updateDriveNumber(int drive) {
-    this.drive = this.drive.substring(0, 3) + drive;
+  public void chooseDriveNumber(final DriveNumber driveNumber) {
+    this.drive = this.drive.substring(0, 3) + driveNumber.drive;
+    driveNumber.drive++;
+    if (driveNumber.drive > 7) {
+      driveNumber.drive = 2;
+    }
   }
 
   public boolean isHardDrive() {
@@ -131,4 +135,8 @@ class DiskImage implements Comparable {
       throw new ClassCastException();
     }
   }
+
+  static class DriveNumber {
+    public int drive = 2;
+  }
 }