diff --git a/Dockerfile b/Dockerfile
index 704ad35..46dd9c4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -73,8 +73,8 @@ VOLUME /var/www/html
 RUN chown -R www-data:www-data /var/www
 
 # Define Grav version and expected SHA1 signature
-ENV GRAV_VERSION 1.5.3
-ENV GRAV_SHA1 2265fd3624278922c009ca2907977d1ccc7a8253
+ENV GRAV_VERSION 1.5.5
+ENV GRAV_SHA1 af0433facdae1afeb1d973a66db2315c5022b10d
 
 # Install grav
 RUN set -ex; \