diff --git a/entrypoint/10-listen-on-ipv6-by-default.sh b/entrypoint/10-listen-on-ipv6-by-default.sh
index 29898b1..1766079 100755
--- a/entrypoint/10-listen-on-ipv6-by-default.sh
+++ b/entrypoint/10-listen-on-ipv6-by-default.sh
@@ -27,7 +27,7 @@ fi
 touch /$DEFAULT_CONF_FILE 2>/dev/null || { entrypoint_log "$ME: info: can not modify /$DEFAULT_CONF_FILE (read-only file system?)"; exit 0; }
 
 # check if the file is already modified, e.g. on a container restart
-grep -q "listen  \[::]\:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
+grep -q "listen  \[::\]:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
 
 if [ -f "/etc/os-release" ]; then
     . /etc/os-release
diff --git a/mainline/alpine-slim/10-listen-on-ipv6-by-default.sh b/mainline/alpine-slim/10-listen-on-ipv6-by-default.sh
index 29898b1..1766079 100755
--- a/mainline/alpine-slim/10-listen-on-ipv6-by-default.sh
+++ b/mainline/alpine-slim/10-listen-on-ipv6-by-default.sh
@@ -27,7 +27,7 @@ fi
 touch /$DEFAULT_CONF_FILE 2>/dev/null || { entrypoint_log "$ME: info: can not modify /$DEFAULT_CONF_FILE (read-only file system?)"; exit 0; }
 
 # check if the file is already modified, e.g. on a container restart
-grep -q "listen  \[::]\:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
+grep -q "listen  \[::\]:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
 
 if [ -f "/etc/os-release" ]; then
     . /etc/os-release
diff --git a/mainline/debian/10-listen-on-ipv6-by-default.sh b/mainline/debian/10-listen-on-ipv6-by-default.sh
index 29898b1..1766079 100755
--- a/mainline/debian/10-listen-on-ipv6-by-default.sh
+++ b/mainline/debian/10-listen-on-ipv6-by-default.sh
@@ -27,7 +27,7 @@ fi
 touch /$DEFAULT_CONF_FILE 2>/dev/null || { entrypoint_log "$ME: info: can not modify /$DEFAULT_CONF_FILE (read-only file system?)"; exit 0; }
 
 # check if the file is already modified, e.g. on a container restart
-grep -q "listen  \[::]\:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
+grep -q "listen  \[::\]:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
 
 if [ -f "/etc/os-release" ]; then
     . /etc/os-release
diff --git a/stable/alpine-slim/10-listen-on-ipv6-by-default.sh b/stable/alpine-slim/10-listen-on-ipv6-by-default.sh
index 29898b1..1766079 100755
--- a/stable/alpine-slim/10-listen-on-ipv6-by-default.sh
+++ b/stable/alpine-slim/10-listen-on-ipv6-by-default.sh
@@ -27,7 +27,7 @@ fi
 touch /$DEFAULT_CONF_FILE 2>/dev/null || { entrypoint_log "$ME: info: can not modify /$DEFAULT_CONF_FILE (read-only file system?)"; exit 0; }
 
 # check if the file is already modified, e.g. on a container restart
-grep -q "listen  \[::]\:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
+grep -q "listen  \[::\]:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
 
 if [ -f "/etc/os-release" ]; then
     . /etc/os-release
diff --git a/stable/debian/10-listen-on-ipv6-by-default.sh b/stable/debian/10-listen-on-ipv6-by-default.sh
index 29898b1..1766079 100755
--- a/stable/debian/10-listen-on-ipv6-by-default.sh
+++ b/stable/debian/10-listen-on-ipv6-by-default.sh
@@ -27,7 +27,7 @@ fi
 touch /$DEFAULT_CONF_FILE 2>/dev/null || { entrypoint_log "$ME: info: can not modify /$DEFAULT_CONF_FILE (read-only file system?)"; exit 0; }
 
 # check if the file is already modified, e.g. on a container restart
-grep -q "listen  \[::]\:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
+grep -q "listen  \[::\]:8080;" /$DEFAULT_CONF_FILE && { entrypoint_log "$ME: info: IPv6 listen already enabled"; exit 0; }
 
 if [ -f "/etc/os-release" ]; then
     . /etc/os-release