diff --git a/images/nginx-spa/Dockerfile b/images/nginx-spa/Dockerfile
index c6a62d8..6df8760 100644
--- a/images/nginx-spa/Dockerfile
+++ b/images/nginx-spa/Dockerfile
@@ -1,4 +1,4 @@
-FROM nginx:stable-alpine
+FROM nginx:stable-alpine@sha256:d6f8c6b38edf2b7c6619718ad7a00caa4ed4741d12ce12550333a28d2b52dc89
 
 RUN sed -i '1idaemon off;' /etc/nginx/nginx.conf