diff --git a/.gitignore b/.gitignore
index 45c23200..063df847 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 /demo/client/node_modules
 /demo/client/package-lock.json
 /demo/server/target
+/demo/server/Rocket.toml
 Cargo.lock
 .DS_Store
 
diff --git a/demo/server/src/main.rs b/demo/server/src/main.rs
index fd981447..eba4c10a 100644
--- a/demo/server/src/main.rs
+++ b/demo/server/src/main.rs
@@ -50,6 +50,8 @@ use std::sync::{Arc, Mutex};
 use std::time::{Duration, Instant};
 use std::u32;
 
+const SUGGESTED_JSON_SIZE_LIMIT: u64 = 32 * 1024 * 1024;
+
 const CUBIC_ERROR_TOLERANCE: f32 = 0.1;
 
 const MESH_LIBRARY_CACHE_SIZE: usize = 16;
@@ -531,7 +533,19 @@ impl<'a> Responder<'a> for Shader {
 fn main() {
     drop(env_logger::init());
 
-    rocket::ignite().mount("/", routes![
+    let rocket = rocket::ignite();
+
+    match rocket.config().limits.get("json") {
+        Some(size) if size >= SUGGESTED_JSON_SIZE_LIMIT => {}
+        None | Some(_) => {
+            eprintln!("warning: the JSON size limit is small; many SVGs will not upload properly");
+            eprintln!("warning: adding the following to `Rocket.toml` is suggested:");
+            eprintln!("warning:    [development]");
+            eprintln!("warning:    limits = {{ json = 33554432 }}");
+        }
+    }
+
+    rocket.mount("/", routes![
         partition_font,
         partition_svg_paths,
         static_index,