diff --git a/Dockerfile b/Dockerfile
index 272cde6..1b7c8d9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -15,7 +15,10 @@ RUN --mount=type=cache,target=/root/go/pkg/mod \
 
 # Copy package files and install npm dependencies (cached unless package.json changes)
 COPY package*.json ./
-RUN --mount=type=cache,target=/root/.npm \
+# npm cache mount renamed from /root/.npm: the old volume held a stale
+# foliate-js tarball (name@version reuse) that --no-cache and builder prune
+# could not evict; a new mount id guarantees a clean fetch.
+RUN --mount=type=cache,target=/root/.npm-cache2 \
   npm install 
 
 # Copy Go mod files (cached unless go.mod changes)