diff --git a/AAXtoMP3 b/AAXtoMP3
index f567698..d5a80a1 100755
--- a/AAXtoMP3
+++ b/AAXtoMP3
@@ -518,9 +518,9 @@ save_metadata() {
     # we use some characters (#) as placeholder, add some new lines,
     # put a ',' after the start value, we calculate the end of each chapter
     # as start+length, and we convert (divide) the time stamps from ms to s.
-    # Then we delete all ':' since they make a filename invalid.
+    # Then we delete all ':' and '/' since they make a filename invalid.
     jq -r '.content_metadata.chapter_info.chapters[] | "Chapter # start: \(.start_offset_ms/1000), end: \((.start_offset_ms+.length_ms)/1000) \n#\n# Title: \(.title)"' "${extra_chapter_file}" \
-      | tr -d ':' >> "$metadata_file"
+      | $SED 's@[:/]@@g' >> "$metadata_file"
     # In case we want to use a single file m4b we need to extract the
     # chapter titles from the .json generated by audible–cli and store
     # them correctly formatted for mp4chaps in a chapter.txt