diff --git a/.github/workflows/build-deploy.yml b/.github/workflows/build-deploy.yml
index 96fbbef87..1c6a8ddbc 100644
--- a/.github/workflows/build-deploy.yml
+++ b/.github/workflows/build-deploy.yml
@@ -32,7 +32,7 @@ jobs:
         run: make install
 
       - name: Build the website
-        run: make build
+        run: make build MODE=production
 
       - name: Set up SSH key
         uses: webfactory/ssh-agent@v0.9.1
diff --git a/.github/workflows/preview.yml b/.github/workflows/preview.yml
index 36a27f899..8763eca23 100644
--- a/.github/workflows/preview.yml
+++ b/.github/workflows/preview.yml
@@ -39,7 +39,7 @@ jobs:
 
       - name: Build the website
         run:
-          make build PREVIEW=true
+          make build MODE=preview
           SITE_URL="https://${BRANCH_NAME}.ep-preview.click"
 
       - name: Set up SSH key
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index d4040f59c..107448844 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -20,6 +20,6 @@ build:
   commands:
     - npm install -g pnpm@latest-10
     - make install
-    - make build PREVIEW=true SITE_URL=$READTHEDOCS_CANONICAL_URL
+    - make build MODE=preview SITE_URL=$READTHEDOCS_CANONICAL_URL
     - mkdir -p $READTHEDOCS_OUTPUT/html
     - cd dist && cp -r * $READTHEDOCS_OUTPUT/html
diff --git a/Makefile b/Makefile
index acf7bfc2e..37b1b7c9a 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ check:
 	pnpm run astro check
 
 build:
-	pnpm build
+	pnpm run astro build --mode $(MODE)
 
 preview: RELEASES_DIR = $(VPS_PREVIEW_PATH)/$(SAFE_BRANCH)/releases
 preview: TARGET = $(RELEASES_DIR)/$(TIMESTAMP)
diff --git a/src/pages/robots.txt.ts b/src/pages/robots.txt.ts
index 6ce8b0465..ef1117032 100644
--- a/src/pages/robots.txt.ts
+++ b/src/pages/robots.txt.ts
@@ -14,6 +14,6 @@ Allow: /
 Sitemap: https://ep2025.europython.eu/sitemap-index.xml
 `;
 
-const isPreview = String(import.meta.env.PREVIEW).toLowerCase() === "true";
+const isPreview = import.meta.env.MODE == "preview";
 export const GET: APIRoute = () =>
   new Response(isPreview ? previewRobots : prodRobots);