diff --git a/CHANGELOG.md b/CHANGELOG.md
index a652b8d..6e912c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # Remodel Changelog
 
 ## Unreleased Changes
+* **Breaking:** `Instance.new` now only works for instances that actually exist.
 * Added `Instance:Clone()` for copying instances all over the place, as is Roblox tradition. ([#12](https://github.com/rojo-rbx/remodel/issues/12))
 * Added `DataModel:GetService()` for finding services and creating them if they don't exist, like Roblox does.
 * Improved error messages in preparation for [#7](https://github.com/rojo-rbx/remodel/issues/7) to be fixed upstream.
diff --git a/src/roblox_api/mod.rs b/src/roblox_api/mod.rs
index 162b56e..da5d526 100644
--- a/src/roblox_api/mod.rs
+++ b/src/roblox_api/mod.rs
@@ -20,6 +20,13 @@ struct Instance;
 impl UserData for Instance {
     fn add_methods<'lua, M: UserDataMethods<'lua, Self>>(methods: &mut M) {
         methods.add_function("new", |context, class_name: String| {
+            if rbx_reflection::get_class_descriptor(&class_name).is_none() {
+                return Err(rlua::Error::external(format!(
+                    "'{}' is not a valid class of Instance.",
+                    class_name,
+                )));
+            }
+
             let master_tree = RemodelContext::get(context)?.master_tree;
             let mut master_handle = master_tree.lock().unwrap();