diff --git a/crates/aldabra-mcp/src/tools.rs b/crates/aldabra-mcp/src/tools.rs
index 69cc65e..356225b 100644
--- a/crates/aldabra-mcp/src/tools.rs
+++ b/crates/aldabra-mcp/src/tools.rs
@@ -3083,9 +3083,8 @@ impl WalletService {
             .and_then(|t| t.get("abs_slot"))
             .and_then(|s| s.as_u64())
             .ok_or_else(|| format!("tip response missing abs_slot: {tip_resp}"))?;
-        let validity_upper_slot = tip_slot
+        let default_validity_upper_slot = tip_slot
             + aldabra_dao::builder::proposal_create::VALIDITY_RANGE_SLOTS;
-        let validity_upper_ms = slot_to_posix_ms(cfg.network, validity_upper_slot)?;
         let tx_lower_ms = slot_to_posix_ms(cfg.network, tip_slot)?;
 
         // AUDIT-2026-05-06 H-3 fix: validator (Proposal/Scripts.hs PVote
@@ -3096,6 +3095,13 @@ impl WalletService {
         // "too early or invalid" script error. Catch lb-vs-voting_start
         // here too.
         //
+        // 2026-05-08 follow-up: when default validity_upper would
+        // overshoot voting_end (e.g. 30-min Sulkta-shape windows where
+        // the 1799-slot validity range starting from current tip lands
+        // past voting_end), clamp validity_upper_slot to voting_end_slot
+        // so the range fits inside the voting window. Same trick the
+        // proposal_advance Draft→VotingReady clamp uses.
+        //
         // Read from prop_datum (target.datum was moved to prop_datum at L2636).
         let voting_start_check = prop_datum.starting_time
             + prop_datum.timing_config.draft_time;
@@ -3108,12 +3114,24 @@ impl WalletService {
                 voting_start_check.saturating_sub(tx_lower_ms)
             ));
         }
-        if validity_upper_ms > voting_end_check {
-            return Err(format!(
-                "tx upper bound {validity_upper_ms} ms is after voting window end {voting_end_check} ms \
-                 — voting closed for proposal #{proposal_id}"
-            ));
-        }
+        let voting_end_slot = posix_ms_to_slot(cfg.network, voting_end_check)?;
+        let validity_upper_slot = if voting_end_slot < default_validity_upper_slot {
+            // Clamp to voting_end. Reject if remaining slots are too narrow
+            // to include the tx (≤ 5 slots is the same threshold the
+            // advance clamp uses).
+            if voting_end_slot <= tip_slot + 5 {
+                return Err(format!(
+                    "voting window has only {} slots remaining (voting_end_slot={voting_end_slot}, \
+                     tip_slot={tip_slot}) — too narrow to include the vote tx; voting period \
+                     effectively closed for proposal #{proposal_id}",
+                    voting_end_slot.saturating_sub(tip_slot),
+                ));
+            }
+            voting_end_slot
+        } else {
+            default_validity_upper_slot
+        };
+        let validity_upper_ms = slot_to_posix_ms(cfg.network, validity_upper_slot)?;
 
         // Wallet utxos with H-5-style asset propagation.
         let wallet_utxos: Vec<DaoWalletUtxo> = {