diff --git a/AAXtoMP3 b/AAXtoMP3
index e9f4eeb..3838c98 100755
--- a/AAXtoMP3
+++ b/AAXtoMP3
@@ -684,7 +684,7 @@ do
         #ffmpeg version 4+ and on the output for all older versions.
         split_input=""
         split_output=""
-        if [ "$(($(ffmpeg -version | sed -E 's/[^0-9]*([0-9]).*/\1/g;1q') > 3))" = "1" ]; then
+        if [ "$(($(ffmpeg -version | $SED -E 's/[^0-9]*([0-9]).*/\1/g;1q') > 3))" = "1" ]; then
           split_input="-ss ${chapter_start%?} -to ${chapter_end}"
         else
           split_output="-ss ${chapter_start%?} -to ${chapter_end}"