diff --git a/src/runtime2/component/component_pdl.rs b/src/runtime2/component/component_pdl.rs
index 14fd2fb0dd6670acda349042897d5b70743c1c47..a73582435ecaeecf86030c59d95f085e71cff9b1 100644
--- a/src/runtime2/component/component_pdl.rs
+++ b/src/runtime2/component/component_pdl.rs
@@ -103,6 +103,17 @@ pub(crate) enum Mode {
     Exit, // exiting: shutdown process started, now waiting until the reference count drops to 0
 }
 
+impl Mode {
+    fn is_in_sync_block(&self) -> bool {
+        use Mode::*;
+
+        match self {
+            Sync | SyncEnd | BlockedGet | BlockedPut | BlockedSelect => true,
+            NonSync | StartExit | BusyExit | Exit => false,
+        }
+    }
+}
+
 struct SelectCase {
     involved_ports: Vec<LocalPortHandle>,
 }
@@ -453,6 +464,11 @@ impl CompPDL {
     fn handle_sync_start(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx) {
         sched_ctx.log("Component starting sync mode");
         self.consensus.notify_sync_start(comp_ctx);
+        for message in self.inbox_main.iter() {
+            if let Some(message) = message {
+                self.consensus.handle_new_data_message(comp_ctx, message);
+            }
+        }
         debug_assert_eq!(self.mode, Mode::NonSync);
         self.mode = Mode::Sync;
     }
@@ -534,6 +550,11 @@ impl CompPDL {
     /// will handle putting it in the correct place, and potentially blocking
     /// the port in case too many messages are being received.
     fn handle_incoming_data_message(&mut self, sched_ctx: &SchedulerCtx, comp_ctx: &mut CompCtx, message: DataMessage) {
+        // Whatever we do, glean information from headers in message
+        if self.mode.is_in_sync_block() {
+            self.consensus.handle_new_data_message(comp_ctx, &message);
+        }
+
         // Check if we can insert it directly into the storage associated with
         // the port
         let target_port_id = message.data_header.target_port;