1 files changed, 1 insertions, 0 deletions

diff --git a/docker/Dockerfile-workers b/docker/Dockerfile-workers

index 0f1570cfb6..84f836ff7b 100644
--- a/docker/Dockerfile-workers
+++ b/docker/Dockerfile-workers
@@ -1,3 +1,4 @@
+# syntax=docker/dockerfile:1
 # Inherit from the official Synapse docker image
 ARG SYNAPSE_VERSION=latest
 FROM matrixdotorg/synapse:$SYNAPSE_VERSION