diff --git a/Dockerfile b/Dockerfile
index 2e3ef0f..da5b052 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,5 +10,6 @@ COPY nginx.conf /etc/nginx/conf.d/default.conf
 COPY web/ /usr/share/nginx/html/
 
 EXPOSE 80
+# 127.0.0.1 on purpose: nginx binds IPv4 only and `localhost` may resolve to ::1
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
-  CMD wget -qO- http://localhost/ >/dev/null || exit 1
+  CMD wget -qO- http://127.0.0.1/ >/dev/null || exit 1