diff --git a/scripts/booksplit b/scripts/booksplit
index 413d37f..b1b06fe 100755
--- a/scripts/booksplit
+++ b/scripts/booksplit
@@ -23,7 +23,7 @@ do
         if echo "mobi" | grep -i -w $extension > /dev/null; then
             mkdir $tmpDir
             $kindleunpack -s "$filename/$filename.$extension" $tmpDir
-            mv "$filename/$filename.$extension" "$filename/$filename.orginal.$extension"
+            mv "$filename/$filename.$extension" "$filename/$filename.orginal_$extension"
             mv "$tmpDir/mobi7-$filename.mobi" "$filename/$filename.mobi"
             mv "$tmpDir/mobi8-$filename.azw3" "$filename/$filename.azw3"
             rm -fr $tmpDir