diff --git a/stacks/fish-s2/compose.yaml b/stacks/fish-s2/compose.yaml
index 04167cf..2cd8118 100644
--- a/stacks/fish-s2/compose.yaml
+++ b/stacks/fish-s2/compose.yaml
@@ -34,6 +34,11 @@ services:
       # 403s on anonymous pulls. Build from source via docker/Dockerfile
       # instead.
       dockerfile: docker/Dockerfile
+      # Multi-stage Dockerfile — `server` stage installs start_server.sh
+      # and exposes the API. The default last stage is `webui` (gradio
+      # only), which crashloops silently because start_server.sh isn't
+      # there. Target=server is what upstream's compose.yml does.
+      target: server
       args:
         # Build args mirror upstream compose.base.yml defaults.
         # CUDA_VER 12.9 + UV_EXTRA cu129 = the CUDA 12.9 PyTorch wheels.