diff --git a/scripts/source-timestamps.sh b/scripts/source-timestamps.sh
index 5bce4de..ce30cf9 100755
--- a/scripts/source-timestamps.sh
+++ b/scripts/source-timestamps.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 #
 # Copyright (C) 2023 University of Luxembourg
@@ -30,13 +30,13 @@ do
 	find "$1" -type f -name '*.md' | grep -v "$NOT_SOURCE_REGEX" | while read file ; do
 		fn=`basename "$file"`
 		dir=`dirname "$file"`
-		tsfn="$fn.timestamp"
+		outfn="$fn.metadata.yml"
 		(
-			echo "making timestamp in '$dir' for file '$fn' ..." >> "$LOGFILE"
+			echo "adding timestamp in '$dir' for file '$fn' ..." >> "$LOGFILE"
 			cd "$dir"
-			if [ -f "$tsfn" ]
+			if grep -q -s "^timestamp:" "$outfn"
 			then echo "... but it already exists; skipping!" >> "$LOGFILE"
-			else git log -n 1 --pretty=format:%cs -- "$fn" > "$tsfn"
+			else git log -n 1 --pretty=format:$'timestamp: %cs\n' -- "$fn" >> "$outfn"
 			fi
 		)
 	done