diff --git a/dockerfiles/discourse-mcp/Dockerfile b/dockerfiles/discourse-mcp/Dockerfile
index 61f5ba2..c071253 100644
--- a/dockerfiles/discourse-mcp/Dockerfile
+++ b/dockerfiles/discourse-mcp/Dockerfile
@@ -2,12 +2,17 @@ FROM node:24-alpine
 
 WORKDIR /app
 
-COPY package.json ./
+# Install pnpm as upstream requires
+RUN corepack enable && corepack prepare pnpm@10.14.0 --activate
 
-RUN npm install
+COPY package.json pnpm-lock.yaml ./
+
+# Install dependencies with pinned SDK version
+RUN pnpm add @modelcontextprotocol/sdk@^1.23.0
+RUN pnpm install --frozen-lockfile
 
 COPY . .
 
-RUN npm run build
+RUN pnpm build
 
 CMD ["node", "dist/index.js"]