diff --git a/consensus/proto_array/src/fork_choice_test_definition/gloas_payload.rs b/consensus/proto_array/src/fork_choice_test_definition/gloas_payload.rs
index 0fb120328c..9a7acbde09 100644
--- a/consensus/proto_array/src/fork_choice_test_definition/gloas_payload.rs
+++ b/consensus/proto_array/src/fork_choice_test_definition/gloas_payload.rs
@@ -718,6 +718,133 @@ pub fn get_gloas_payload_received_interleaving_test_definition() -> ForkChoiceTe
 mod tests {
     use super::*;
 
+    fn gloas_fork_boundary_spec() -> ChainSpec {
+        let mut spec = MainnetEthSpec::default_spec();
+        spec.proposer_score_boost = Some(50);
+        spec.gloas_fork_epoch = Some(Epoch::new(1));
+        spec
+    }
+
+    /// Gloas fork boundary: a chain starting pre-Gloas (V17 nodes) that crosses into
+    /// Gloas (V29 nodes). The head should advance through the fork boundary.
+    ///
+    /// Parameters:
+    /// - `skip_first_gloas_slot`: if true, there is no block at the first Gloas slot (slot 32);
+    ///    the first V29 block appears at slot 33.
+    /// - `first_gloas_block_full`: if true, the first V29 block extends the parent V17 node's
+    ///    EL chain (Full parent payload status). If false, it doesn't (Empty).
+    fn get_gloas_fork_boundary_test_definition(
+        skip_first_gloas_slot: bool,
+        first_gloas_block_full: bool,
+    ) -> ForkChoiceTestDefinition {
+        let mut ops = vec![];
+
+        // Block at slot 31 — last pre-Gloas slot. Created as a V17 node because
+        // gloas_fork_epoch = 1 → Gloas starts at slot 32.
+        //
+        // The test harness sets execution_status = Optimistic(ExecutionBlockHash::from_root(root)),
+        // so this V17 node's EL block hash = ExecutionBlockHash::from_root(get_root(1)).
+        ops.push(Operation::ProcessBlock {
+            slot: Slot::new(31),
+            root: get_root(1),
+            parent_root: get_root(0),
+            justified_checkpoint: get_checkpoint(0),
+            finalized_checkpoint: get_checkpoint(0),
+            execution_payload_parent_hash: None,
+            execution_payload_block_hash: None,
+        });
+
+        // First Gloas block (V29 node).
+        let gloas_slot = if skip_first_gloas_slot { 33 } else { 32 };
+
+        // For Full: execution_payload_parent_hash must match the V17 parent's EL hash.
+        // The V17 parent's EL hash = ExecutionBlockHash::from_root(get_root(1)) = get_hash(1).
+        // For Empty: use a non-matching hash.
+        let parent_hash = if first_gloas_block_full {
+            get_hash(1)
+        } else {
+            get_hash(99)
+        };
+
+        ops.push(Operation::ProcessBlock {
+            slot: Slot::new(gloas_slot),
+            root: get_root(2),
+            parent_root: get_root(1),
+            justified_checkpoint: get_checkpoint(0),
+            finalized_checkpoint: get_checkpoint(0),
+            execution_payload_parent_hash: Some(parent_hash),
+            execution_payload_block_hash: Some(get_hash(2)),
+        });
+
+        // Verify the parent_payload_status is correctly set.
+        let expected_parent_status = if first_gloas_block_full {
+            PayloadStatus::Full
+        } else {
+            PayloadStatus::Empty
+        };
+        ops.push(Operation::AssertParentPayloadStatus {
+            block_root: get_root(2),
+            expected_status: expected_parent_status,
+        });
+
+        // Mark root 2's execution payload as received so the Full virtual child exists.
+        ops.push(Operation::ProcessExecutionPayload {
+            block_root: get_root(2),
+        });
+
+        // Extend the chain with another V29 block (Full child of root 2).
+        ops.push(Operation::ProcessBlock {
+            slot: Slot::new(gloas_slot + 1),
+            root: get_root(3),
+            parent_root: get_root(2),
+            justified_checkpoint: get_checkpoint(0),
+            finalized_checkpoint: get_checkpoint(0),
+            execution_payload_parent_hash: Some(get_hash(2)),
+            execution_payload_block_hash: Some(get_hash(3)),
+        });
+
+        // Head should advance to the tip of the chain through the fork boundary.
+        ops.push(Operation::FindHead {
+            justified_checkpoint: get_checkpoint(0),
+            finalized_checkpoint: get_checkpoint(0),
+            justified_state_balances: vec![1],
+            expected_head: get_root(3),
+            current_slot: Slot::new(gloas_slot + 1),
+            expected_payload_status: None,
+        });
+
+        ForkChoiceTestDefinition {
+            finalized_block_slot: Slot::new(0),
+            justified_checkpoint: get_checkpoint(0),
+            finalized_checkpoint: get_checkpoint(0),
+            operations: ops,
+            // Genesis is V17 (slot 0 < Gloas fork slot 32), these are unused for V17.
+            execution_payload_parent_hash: None,
+            execution_payload_block_hash: None,
+            spec: Some(gloas_fork_boundary_spec()),
+        }
+    }
+
+    #[test]
+    fn fork_boundary_no_skip_full() {
+        get_gloas_fork_boundary_test_definition(false, true).run();
+    }
+
+    #[test]
+    fn fork_boundary_no_skip_empty() {
+        get_gloas_fork_boundary_test_definition(false, false).run();
+    }
+
+    #[test]
+    fn fork_boundary_skip_first_gloas_slot_full() {
+        get_gloas_fork_boundary_test_definition(true, true).run();
+    }
+
+    #[test]
+    fn fork_boundary_skip_first_gloas_slot_empty() {
+        get_gloas_fork_boundary_test_definition(true, false).run();
+    }
+
     #[test]
     fn chain_following() {
         let test = get_gloas_chain_following_test_definition();