diff --git a/docker/build.sh b/docker/build.sh
new file mode 100755
index 00000000..85369368
--- /dev/null
+++ b/docker/build.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+# Build the chatmail Docker image with the current git hash baked in.
+# Usage: ./docker/build.sh [extra docker-compose build args...]
+#
+# .git/ is excluded from the build context (.dockerignore) so the hash
+# must be passed as a build arg from the host.
+
+export GIT_HASH=$(git rev-parse --short HEAD)
+exec docker compose build "$@"