diff --git a/docker/fork-cuda.Containerfile b/docker/fork-cuda.Containerfile
index 3bb7d690..57e2e7d5 100644
--- a/docker/fork-cuda.Containerfile
+++ b/docker/fork-cuda.Containerfile
@@ -16,8 +16,10 @@ ARG BASE_TAG=server-cuda-b9821
 # ---- Stage 1: build the Svelte UI (embedded into the binary) ----
 FROM node:22-bookworm-slim AS ui
 WORKDIR /src/ui-svelte
-# Install deps first for layer caching.
-COPY ui-svelte/package.json ui-svelte/package-lock.json ./
+# Install deps first for layer caching. .npmrc carries legacy-peer-deps=true,
+# which the project relies on (tailwind/vite peer ranges), so copy it before
+# npm ci or the strict resolver fails with ERESOLVE.
+COPY ui-svelte/package.json ui-svelte/package-lock.json ui-svelte/.npmrc ./
 RUN npm ci
 COPY ui-svelte/ ./
 # `npm run build` is `vite build --emptyOutDir`; vite.config.ts writes to