diff --git a/.env.example b/.env.example
index 356e653b..8b1a5356 100644
--- a/.env.example
+++ b/.env.example
@@ -21,6 +21,14 @@ NODE_ENV=development
 # [OPTIONAL] Server port (default: 3000)
 PORT=3000
 
+# [OPTIONAL] Maximum request body size for the Node server (default: 512K)
+# adapter-node rejects larger request bodies with HTTP 413 before they reach the app,
+# which silently breaks file uploads (conference base PDFs / images can be several MB;
+# the Zod schema validates base PDFs up to 10MB each, and one save may include several).
+# Set this above the largest expected upload. Accepts K/M/G suffixes; "Infinity" disables.
+# Not enforced by the Vite dev server — only by the production (adapter-node) build.
+# BODY_SIZE_LIMIT=64M
+
 # [OPTIONAL] Public origin of the application (e.g. https://delegator.munify.cloud)
 # SvelteKit uses this for CSRF protection on form submissions and POST requests.
 # If not set, SvelteKit infers it from the Host header, which works when your reverse
diff --git a/Dockerfile b/Dockerfile
index 4bdfcc8a..ad40317c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -27,5 +27,11 @@ RUN bun run build:app && bun run check
 
 USER bun
 ENV NODE_ENV=production
+# adapter-node caps request bodies at 512K by default and rejects anything larger with
+# HTTP 413 before the request reaches the app. Conference document/image uploads (base
+# PDFs are validated up to 10MB each in the Zod schema, and several can be sent in one
+# save) exceed that. Raise the limit so uploads actually reach the server. Overridable at
+# runtime via the BODY_SIZE_LIMIT env var (see .env.example).
+ENV BODY_SIZE_LIMIT=64M
 EXPOSE 3000/tcp
 CMD ["sh", "-c", "bunx prisma migrate deploy && bun ./build/index.js"]