diff --git a/src/runtime2/scheduler.rs b/src/runtime2/scheduler.rs
index 22299972b63d32556f9f855b82fd5f9e73066e32..e822bdff686170be618cdaab571777e698bd80b6 100644
--- a/src/runtime2/scheduler.rs
+++ b/src/runtime2/scheduler.rs
@@ -1,6 +1,7 @@
 use std::collections::VecDeque;
 use std::sync::Arc;
 use std::sync::atomic::Ordering;
+use crate::protocol::eval::EvalError;
 
 use super::{ScheduledConnector, RuntimeInner, ConnectorId, ConnectorKey};
 use super::port::{Port, PortState, PortIdLocal};
@@ -393,6 +394,7 @@ pub(crate) struct ComponentCtx {
     changed_in_sync: bool,
     outbox: VecDeque<Message>,
     state_changes: VecDeque<ComponentStateChange>,
+
     // Workspaces that may be used by components to (generally) prevent
     // allocations. Be a good scout and leave it empty after you've used it.
     // TODO: Move to scheduler ctx, this is the wrong place
@@ -431,6 +433,14 @@ impl ComponentCtx {
         self.state_changes.push_back(ComponentStateChange::CreatedPort(port))
     }
 
+    /// Notify the runtime of an error. Note that this will not perform any
+    /// special action beyond printing the error. The component is responsible
+    /// for waiting until it is appropriate to shut down (i.e. being outside
+    /// of a sync region) and returning the `Exit` scheduling code.
+    pub(crate) fn push_error(&mut self, error: EvalError) {
+
+    }
+
     #[inline]
     pub(crate) fn get_ports(&self) -> &[Port] {
         return self.ports.as_slice();
@@ -462,9 +472,17 @@ impl ComponentCtx {
 
     /// Submit a message for the scheduler to send to the appropriate receiver.
     /// May only be called inside of a sync block.
-    pub(crate) fn submit_message(&mut self, contents: Message) {
+    pub(crate) fn submit_message(&mut self, contents: Message) -> Result<(), ()> {
         debug_assert!(self.is_in_sync);
+        if let Some(port_id) = contents.source_port() {
+            if self.get_port_by_id(port_id).is_none() {
+                // We don't own the port
+                return Err(());
+            }
+        }
+
         self.outbox.push_back(contents);
+        return Ok(());
     }
 
     /// Notify that component just finished a sync block. Like