diff --git a/refactor_music_library.sh b/refactor_music_library.sh
index 60da58f..42f8de4 100755
--- a/refactor_music_library.sh
+++ b/refactor_music_library.sh
@@ -20,6 +20,8 @@
 DIR="`pwd`"
 PROG="$(basename -- "${BASH_SOURCE[0]}")"
 
+EXT=".mp3"
+
 FAIL=".$PROG.exit-error"
 
 OLD="OLD"