diff --git a/docker/etc/s6-overlay/s6-rc.d/04-nqptp/run b/docker/etc/s6-overlay/s6-rc.d/04-nqptp/run
index 0d41862f..6930a2e1 100644
--- a/docker/etc/s6-overlay/s6-rc.d/04-nqptp/run
+++ b/docker/etc/s6-overlay/s6-rc.d/04-nqptp/run
@@ -1,3 +1,7 @@
 #!/command/with-contenv sh
 echo "Starting nqptp"
-exec /usr/local/bin/nqptp -ipv4-only
+if [ -z ${IPV4ONLY+x} ]; then
+    exec /usr/local/bin/nqptp
+else
+    exec /usr/local/bin/nqptp -ipv4-only
+fi
\ No newline at end of file