diff --git a/src/runtime2/consensus.rs b/src/runtime2/consensus.rs
index b9980cbe237784ea95c05c76c986e651322ba3b3..7da2a179ad5808552f3503de09e651a7d5badf20 100644
--- a/src/runtime2/consensus.rs
+++ b/src/runtime2/consensus.rs
@@ -186,7 +186,12 @@ impl Consensus {
                 target_port: port_info.peer_id,
                 content: SyncPortContent::NotificationWave,
             };
-            ctx.submit_message(Message::SyncPort(message));
+
+            // Note: submitting the message might fail. But we're attempting to
+            // handle the error anyway.
+            // TODO: Think about this a second time: how do we make sure the
+            //  entire network will fail if we reach this condition
+            let _unused = ctx.submit_message(Message::SyncPort(message));
         }
 
         return maybe_conclusion;
@@ -265,7 +270,7 @@ impl Consensus {
             let channel_id = port_desc.channel_id;
 
             if !self.encountered_ports.contains(&self_port_id) {
-                ctx.submit_message(Message::SyncPort(SyncPortMessage {
+                let message = SyncPortMessage {
                     sync_header: SyncHeader{
                         sending_component_id: ctx.id,
                         highest_component_id: self.highest_connector_id,
@@ -274,8 +279,17 @@ impl Consensus {
                     source_port: self_port_id,
                     target_port: peer_port_id,
                     content: SyncPortContent::SilentPortNotification,
-                }));
-                self.encountered_ports.push(self_port_id);
+                };
+                match ctx.submit_message(Message::SyncPort(message)) {
+                    Ok(_) => {
+                        self.encountered_ports.push(self_port_id);
+                    },
+                    Err(_) => {
+                        // Seems like we were done with this branch, but one of
+                        // the silent ports (in scope) is actually closed
+                        return self.notify_of_fatal_branch(branch_id, ctx);
+                    }
+                }
             }
 
             target_mapping.push((
@@ -469,7 +483,9 @@ impl Consensus {
                         target_port: port_desc.peer_id,
                         content: SyncPortContent::NotificationWave,
                     };
-                    ctx.submit_message(Message::SyncPort(message)).unwrap();
+                    // As with the other SyncPort where we throw away the
+                    // result: we're dealing with an error here anyway
+                    let _unused = ctx.submit_message(Message::SyncPort(message));
                 }
             }
         }
@@ -566,7 +582,7 @@ impl Consensus {
                     target_component_id: peer.id,
                     content: SyncCompContent::Notification,
                 };
-                ctx.submit_message(Message::SyncComp(message));
+                ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
             }
 
             // But also send our locally combined solution
@@ -579,7 +595,7 @@ impl Consensus {
                 target_component_id: sync_header.sending_component_id,
                 content: SyncCompContent::Notification
             };
-            ctx.submit_message(Message::SyncComp(message));
+            ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
         } // else: exactly equal, so do nothing
 
         return true;
@@ -665,7 +681,7 @@ impl Consensus {
                 target_component_id: self.highest_connector_id,
                 content,
             };
-            ctx.submit_message(Message::SyncComp(message));
+            ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
         }
 
         return None;
@@ -690,7 +706,7 @@ impl Consensus {
                 target_component_id: connector_id,
                 content: SyncCompContent::GlobalSolution(global_solution.clone()),
             };
-            ctx.submit_message(Message::SyncComp(message));
+            ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
         }
 
         debug_assert!(my_final_branch_id.is_valid());
@@ -716,7 +732,7 @@ impl Consensus {
                         target_component_id: presence.added_by,
                         content: SyncCompContent::GlobalFailure,
                     };
-                    ctx.submit_message(Message::SyncComp(message));
+                    ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
                 }
             }
         }
@@ -748,7 +764,7 @@ impl Consensus {
                 target_component_id: self.highest_connector_id,
                 content: SyncCompContent::PartialSolution(partial_solution),
             };
-            ctx.submit_message(Message::SyncComp(message));
+            ctx.submit_message(Message::SyncComp(message)).unwrap(); // unwrap: sending to component instead of through channel
         }
     }
 }