diff --git a/crates/aldabra-dao/src/builder/proposal_create.rs b/crates/aldabra-dao/src/builder/proposal_create.rs
index dd962dd..d569e8c 100644
--- a/crates/aldabra-dao/src/builder/proposal_create.rs
+++ b/crates/aldabra-dao/src/builder/proposal_create.rs
@@ -352,12 +352,21 @@ pub fn build_unsigned_proposal_create(
         starting_time: args.starting_time_ms,
     };
 
-    // New stake datum: copy old, append Created lock for the new proposal.
-    let mut new_stake = args.stake_in.datum.clone();
-    new_stake.locked_by.push(ProposalLock {
+    // New stake datum: copy old, PREPEND a Created lock for the new
+    // proposal. Order matters — the stake validator's ppermitVote uses
+    // `pcons NEW_LOCK old_locks` (head-cons, NOT append). If we append
+    // and the input had pre-existing locks, the chain rejects with
+    // CekError on the stake validator. Caught 2026-05-08 trying to
+    // create proposal #1 while the stake still held a Created lock
+    // from proposal #0; cosign + vote builders already prepend.
+    let mut new_locks = Vec::with_capacity(args.stake_in.datum.locked_by.len() + 1);
+    new_locks.push(ProposalLock {
         proposal_id: new_proposal_id,
         action: ProposalAction::Created,
     });
+    new_locks.extend(args.stake_in.datum.locked_by.iter().cloned());
+    let mut new_stake = args.stake_in.datum.clone();
+    new_stake.locked_by = new_locks;
 
     let new_governor_datum_pd = new_governor.to_plutus_data()?;
     let new_proposal_datum_pd = new_proposal.to_plutus_data()?;