diff --git a/src/runtime2/component/component_context.rs b/src/runtime2/component/component_context.rs
index c0ec092a208d6353fa9f266ed939cc749fb9288a..c02320d58b382798cd59dff48078bd4f00e9b7d6 100644
--- a/src/runtime2/component/component_context.rs
+++ b/src/runtime2/component/component_context.rs
@@ -14,13 +14,19 @@ pub enum PortInstruction {
 
 #[derive(Debug)]
 pub struct Port {
+    // Identifiers
     pub self_id: PortId,
     pub peer_comp_id: CompId, // eventually consistent
     pub peer_port_id: PortId, // eventually consistent
+    // Generic operating state
     pub kind: PortKind,
     pub state: PortState,
-    pub last_instruction: PortInstruction, // used during sync round in case port ends up being closed for error reporting
-    pub close_at_sync_end: bool, // used during sync round when receiving a `ClosePort(not_in_sync_round)` message
+    // State tracking for error detection and error handling
+    pub last_instruction: PortInstruction, // used during sync round to detect port-closed-during-sync errors
+    pub received_message_for_sync: bool, // used during sync round to detect port-closed-before-sync errors
+    pub close_at_sync_end: bool, // set during sync round when receiving a port-closed-after-sync message
+    // Debugging flag to make sure each port is properly associated and
+    // disassociated with a peer component
     #[cfg(debug_assertions)] pub(crate) associated_with_peer: bool,
 }
 
@@ -72,6 +78,7 @@ impl CompCtx {
             peer_comp_id: self.id,
             last_instruction: PortInstruction::None,
             close_at_sync_end: false,
+            received_message_for_sync: false,
             #[cfg(debug_assertions)] associated_with_peer: false,
         });
         self.ports.push(Port{
@@ -82,6 +89,7 @@ impl CompCtx {
             peer_comp_id: self.id,
             last_instruction: PortInstruction::None,
             close_at_sync_end: false,
+            received_message_for_sync: false,
             #[cfg(debug_assertions)] associated_with_peer: false,
         });
 
@@ -95,6 +103,7 @@ impl CompCtx {
             self_id, peer_comp_id, peer_port_id, kind, state,
             last_instruction: PortInstruction::None,
             close_at_sync_end: false,
+            received_message_for_sync: false,
             #[cfg(debug_assertions)] associated_with_peer: false,
         });
         return LocalPortHandle(self_id);