diff --git a/Dockerfile b/Dockerfile
index fa73ac9..7fefc18 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,7 +16,7 @@ RUN set -ex; \
     cd /flox/backend; \
     composer install;
 
-FROM php:7.3.20-fpm-buster@sha256:a3e10befa565667a96b25b34f5cb7729c41be3eb3e2add67924e736c343735f7
+FROM php:7.3.21-fpm-buster@sha256:c71d34607c3363af6d831f7b3821e060e6445738b0866d6103d9b5cf8f0d6b36
 COPY --from=composer /flox /usr/share/flox
 RUN set -ex; \
     \