diff --git a/cannamanage-frontend/Dockerfile b/cannamanage-frontend/Dockerfile
index ddd9da0..238f76b 100644
--- a/cannamanage-frontend/Dockerfile
+++ b/cannamanage-frontend/Dockerfile
@@ -12,6 +12,14 @@ COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 
 ENV NEXT_TELEMETRY_DISABLED=1
+# Provide placeholder build-time values so Next.js SSG doesn't crash on undefined URLs
+# Real values are injected at runtime via docker-compose environment:
+ARG NEXTAUTH_URL=http://localhost:3000
+ARG NEXTAUTH_SECRET=build-time-placeholder-secret-minimum-32-chars
+ARG BACKEND_URL=http://localhost:8080
+ENV NEXTAUTH_URL=${NEXTAUTH_URL}
+ENV NEXTAUTH_SECRET=${NEXTAUTH_SECRET}
+ENV BACKEND_URL=${BACKEND_URL}
 RUN pnpm build
 
 FROM base AS runner