diff --git a/.version b/.version
index 68e69e405e..3b1fc7950f 100644
--- a/.version
+++ b/.version
@@ -1 +1 @@
-2.15.0
+2.15.1
diff --git a/README.md b/README.md
index 0af3edecd8..5cd9be1c96 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 <p align="center">
 	<img src="https://nginxproxymanager.com/github.png">
 	<br><br>
-	<img src="https://img.shields.io/badge/version-2.15.0-green.svg?style=for-the-badge">
+	<img src="https://img.shields.io/badge/version-2.15.1-green.svg?style=for-the-badge">
 	<a href="https://hub.docker.com/repository/docker/jc21/nginx-proxy-manager">
 		<img src="https://img.shields.io/docker/stars/jc21/nginx-proxy-manager.svg?style=for-the-badge">
 	</a>
diff --git a/docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/50-ipv6.sh b/docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/50-ipv6.sh
index edc9649c9b..36387a98dc 100755
--- a/docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/50-ipv6.sh
+++ b/docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/50-ipv6.sh
@@ -8,6 +8,10 @@ set -e
 
 log_info 'IPv6 ...'
 
+is_mounted() {
+	awk -v p="$1" '$5 == p { found=1 } END { exit !found }' /proc/self/mountinfo
+}
+
 process_folder () {
 	FILES=$(find "$1" -type f -name "*.conf")
 	SED_REGEX=
@@ -26,7 +30,10 @@ process_folder () {
 	do
 		echo "- ${FILE}"
 		TMPFILE="${FILE}.tmp"
-		if sed -E "$SED_REGEX" "$FILE" > "$TMPFILE" && [ -s "$TMPFILE" ]; then
+
+		if is_mounted "${FILE}"; then
+			echo "WARNING: skipping ${FILE} — mounted file" >&2
+		elif sed -E "$SED_REGEX" "$FILE" > "$TMPFILE" && [ -s "$TMPFILE" ]; then
 			mv "$TMPFILE" "$FILE"
 		else
 			echo "WARNING: skipping ${FILE} — sed produced empty output" >&2