diff --git a/Dockerfile b/Dockerfile
index 060f51e..3af5adc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM openresty/openresty:1.19.9.1-buster@sha256:c959c008c9a2f43e2833cd098dcfd5e1f761b682ac823b8619fd036e70eb691c
+FROM openresty/openresty:1.21.4.1-buster@sha256:fd7f2f0210b6d02bdf541e9c4b3ce08c9cf01f8fc0899bb134b68220021f77e1
 
 COPY nginx.conf.template /
 COPY entrypoint.sh /