diff --git a/sim-rs/CHANGELOG.md b/sim-rs/CHANGELOG.md
index 236331873..765db9a56 100644
--- a/sim-rs/CHANGELOG.md
+++ b/sim-rs/CHANGELOG.md
@@ -1,10 +1,11 @@
 # Changelog
 
-## Unreleased
+## v1.3.1
 
 ### Linear Leios
 - Add some protocol-level tests
 - Fix bug; transactions with conflicts referenced by EBs did not propagate far enough
+- Fix bug; transactions were included in both RBs and their endorsed EBs
 
 ### Other
 
diff --git a/sim-rs/Cargo.lock b/sim-rs/Cargo.lock
index 9a3ad36a7..39292683f 100644
--- a/sim-rs/Cargo.lock
+++ b/sim-rs/Cargo.lock
@@ -1229,7 +1229,7 @@ dependencies = [
 
 [[package]]
 name = "sim-cli"
-version = "1.3.0"
+version = "1.3.1"
 dependencies = [
  "anyhow",
  "async-compression",
@@ -1257,7 +1257,7 @@ dependencies = [
 
 [[package]]
 name = "sim-core"
-version = "1.3.0"
+version = "1.3.1"
 dependencies = [
  "anyhow",
  "async-stream",
diff --git a/sim-rs/sim-cli/Cargo.toml b/sim-rs/sim-cli/Cargo.toml
index f01e4a3ad..93f3545f9 100644
--- a/sim-rs/sim-cli/Cargo.toml
+++ b/sim-rs/sim-cli/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sim-cli"
-version = "1.3.0"
+version = "1.3.1"
 edition = "2024"
 default-run = "sim-cli"
 rust-version = "1.88"
diff --git a/sim-rs/sim-core/Cargo.toml b/sim-rs/sim-core/Cargo.toml
index c20bb7836..d83e366bd 100644
--- a/sim-rs/sim-core/Cargo.toml
+++ b/sim-rs/sim-core/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sim-core"
-version = "1.3.0"
+version = "1.3.1"
 edition = "2024"
 rust-version = "1.88"
 
diff --git a/sim-rs/sim-core/src/sim/linear_leios.rs b/sim-rs/sim-core/src/sim/linear_leios.rs
index d25856d19..3fc4cafb7 100644
--- a/sim-rs/sim-core/src/sim/linear_leios.rs
+++ b/sim-rs/sim-core/src/sim/linear_leios.rs
@@ -538,22 +538,27 @@ impl LinearLeiosNode {
                 return None;
             }
 
-            let eb_id = self.leios.ebs_by_rb.get(&rb_id)?;
-            let votes = self.leios.votes_by_eb.get(eb_id)?;
+            let eb_id = *self.leios.ebs_by_rb.get(&rb_id)?;
+            let votes = self.leios.votes_by_eb.get(&eb_id)?;
             let total_votes = votes.values().copied().sum::<usize>();
             if (total_votes as u64) < self.sim_config.vote_threshold {
                 // Not enough votes. No endorsement.
                 return None;
             }
+            let votes = votes.clone();
 
-            // We haven't necessarily finished validating this EB, or even received it and its contents.
-            // That won't stop us from generating the endorsement, though it'll make us produce an empty block.
-            if !self.is_eb_validated(*eb_id) {
-                self.leios.incomplete_onchain_ebs.insert(*eb_id);
+            if let Some(eb) = self.get_validated_eb(eb_id) {
+                // If we're endorsing this EB, clear its TXs out of the mempool now
+                // so that we don't include them in new blocks.
+                self.remove_eb_txs_from_mempool(&eb);
+            } else {
+                // We haven't finished validating this EB, maybe even haven't received it and its contents.
+                // That won't stop us from generating the endorsement, though it'll make us produce an empty block.
+                self.leios.incomplete_onchain_ebs.insert(eb_id);
             }
 
             Some(Endorsement {
-                eb: *eb_id,
+                eb: eb_id,
                 size_bytes: self.sim_config.sizes.cert(votes.len()),
                 votes: votes.clone(),
             })
@@ -1094,13 +1099,18 @@ impl LinearLeiosNode {
     }
 
     fn is_eb_validated(&self, eb_id: EndorserBlockId) -> bool {
-        matches!(
-            self.leios.ebs.get(&eb_id),
+        self.get_validated_eb(eb_id).is_some()
+    }
+
+    fn get_validated_eb(&self, eb_id: EndorserBlockId) -> Option<Arc<EndorserBlock>> {
+        match self.leios.ebs.get(&eb_id) {
             Some(EndorserBlockView::Received {
+                eb,
                 validated: true,
                 ..
-            })
-        )
+            }) => Some(eb.clone()),
+            _ => None,
+        }
     }
 }
 
diff --git a/sim-rs/sim-core/src/sim/tests/linear_leios.rs b/sim-rs/sim-core/src/sim/tests/linear_leios.rs
index df3f7eb5d..fe800bf4c 100644
--- a/sim-rs/sim-core/src/sim/tests/linear_leios.rs
+++ b/sim-rs/sim-core/src/sim/tests/linear_leios.rs
@@ -1,6 +1,7 @@
 use std::{
     collections::{BTreeMap, HashMap},
     sync::Arc,
+    time::Duration,
 };
 
 use rand::{RngCore, SeedableRng};
@@ -30,6 +31,8 @@ fn new_sim_config(topology: RawTopology) -> Arc<SimConfiguration> {
         value: tx_size as f64,
     };
     params.tx_max_size_bytes = tx_size;
+    // it takes two votes to certify an EB
+    params.vote_threshold = 2;
     let topology = topology.into();
     Arc::new(SimConfiguration::build(params, topology).unwrap())
 }
@@ -154,6 +157,14 @@ impl TestDriver {
         tx
     }
 
+    pub fn produce_txs<const N: usize>(
+        &mut self,
+        node_id: NodeId,
+        conflict: bool,
+    ) -> [Arc<Transaction>; N] {
+        [(); N].map(|_| self.produce_tx(node_id, conflict))
+    }
+
     pub fn win_next_rb_lottery(&mut self, node_id: NodeId, result: u64) {
         self.lottery
             .get(&node_id)
@@ -249,6 +260,13 @@ impl TestDriver {
         self.expect_cpu_task(node, CpuTask::EBBlockValidated(eb, self.time.now()));
     }
 
+    pub fn expect_vote_bundle_sent(&mut self, from: NodeId, to: NodeId, votes: Arc<VoteBundle>) {
+        self.expect_message(from, to, Message::AnnounceVotes(votes.id));
+        self.expect_message(to, from, Message::RequestVotes(votes.id));
+        self.expect_message(from, to, Message::Votes(votes.clone()));
+        self.expect_cpu_task(to, CpuTask::VTBundleValidated(from, votes));
+    }
+
     pub fn expect_message(
         &mut self,
         from: NodeId,
@@ -394,12 +412,10 @@ fn should_produce_rbs_and_ebs() {
     let node2 = sim.id_for("node-2");
 
     // Node 1 produces three transactions, Node 2 should request them all
-    let tx1_1 = sim.produce_tx(node1, false);
-    sim.expect_tx_sent(node1, node2, tx1_1.clone());
-    let tx1_2 = sim.produce_tx(node1, false);
-    sim.expect_tx_sent(node1, node2, tx1_2.clone());
-    let tx1_3 = sim.produce_tx(node1, false);
-    sim.expect_tx_sent(node1, node2, tx1_3.clone());
+    let [tx1_1, tx1_2, tx1_3] = sim.produce_txs(node1, false);
+    for tx in [&tx1_1, &tx1_2, &tx1_3] {
+        sim.expect_tx_sent(node1, node2, tx.clone());
+    }
 
     sim.win_next_rb_lottery(node1, 0);
     sim.next_slot();
@@ -451,9 +467,7 @@ fn should_repropagate_conflicting_transactions_from_eb() {
     let node3 = sim.id_for("node-3");
 
     // Node 1 produces 3 transactions
-    let tx1_1 = sim.produce_tx(node1, false);
-    let tx1_2 = sim.produce_tx(node1, false);
-    let tx1_3 = sim.produce_tx(node1, false);
+    let [tx1_1, tx1_2, tx1_3] = sim.produce_txs(node1, false);
 
     // Node 2 produces a transaction which conflicts with Node 1's final transaction
     let tx2 = sim.produce_tx(node2, true);
@@ -501,9 +515,7 @@ fn should_vote_for_eb() {
     let node1 = sim.id_for("node-1");
     let node2 = sim.id_for("node-2");
 
-    let txs = (0..3)
-        .map(|_| sim.produce_tx(node1, false))
-        .collect::<Vec<_>>();
+    let txs: [_; 3] = sim.produce_txs(node1, false);
     for tx in &txs {
         sim.expect_tx_sent(node1, node2, tx.clone());
     }
@@ -521,3 +533,57 @@ fn should_vote_for_eb() {
     let vote = sim.expect_cpu_task_matching(node2, is_new_vote_task);
     assert_eq!(*vote.ebs.first_key_value().unwrap().0, eb.id());
 }
+
+#[test]
+fn should_not_include_tx_twice() {
+    let topology = new_topology(vec![
+        ("node-1", new_node(Some(1000), vec!["node-2"])),
+        ("node-2", new_node(Some(1000), vec!["node-1"])),
+    ]);
+    let mut sim = TestDriver::new(topology);
+    let node1 = sim.id_for("node-1");
+    let node2 = sim.id_for("node-2");
+
+    let [rb_tx1, rb_tx2, eb_tx] = sim.produce_txs(node1, false);
+    for tx in [&rb_tx1, &rb_tx2, &eb_tx] {
+        sim.expect_tx_sent(node1, node2, tx.clone());
+    }
+
+    sim.win_next_vote_lottery(node1, 0);
+    sim.win_next_vote_lottery(node2, 0);
+
+    // Node 1 produces an RB containing two transactions, and an EB containing a third
+    sim.win_next_rb_lottery(node1, 0);
+    sim.next_slot();
+    let (rb, eb) = sim.expect_cpu_task_matching(node1, is_new_rb_task);
+    let eb = eb.expect("node did not produce EB");
+    assert!(eb.txs.contains(&eb_tx));
+
+    // Node 2 receives and validates the RB and EB
+    sim.expect_rb_and_eb_sent(node1, node2, rb.clone(), Some(eb.clone()));
+    sim.expect_eb_validated(node2, eb.clone());
+
+    // Nodes 1 and 2 both vote for the EB
+    sim.advance_time_to(sim.now() + (sim.config.header_diffusion_time * 3));
+    let votes_1 = sim.expect_cpu_task_matching(node1, is_new_vote_task);
+    sim.expect_vote_bundle_sent(node1, node2, votes_1);
+    let votes_2 = sim.expect_cpu_task_matching(node2, is_new_vote_task);
+    sim.expect_vote_bundle_sent(node2, node1, votes_2);
+
+    // After enough time has elapsed to include the EB in a new RB, Node 2 mints a new RB
+    sim.advance_time_to(
+        sim.now()
+            + Duration::from_secs(sim.config.linear_diffuse_stage_length)
+            + Duration::from_secs(sim.config.linear_vote_stage_length),
+    );
+    sim.win_next_rb_lottery(node2, 0);
+    sim.next_slot();
+    let (rb, new_eb) = sim.expect_cpu_task_matching(node2, is_new_rb_task);
+
+    // This RB endorses the previous EB (including its transaction on the chain)
+    assert_eq!(rb.endorsement.as_ref().map(|e| e.eb), Some(eb.id()));
+
+    // And it does not include any transactions of its own
+    assert!(rb.transactions.is_empty());
+    assert_eq!(new_eb, None);
+}