diff --git a/beacon_node/beacon_chain/tests/store_tests.rs b/beacon_node/beacon_chain/tests/store_tests.rs
index 8e10f0e85f..2c8db586b0 100644
--- a/beacon_node/beacon_chain/tests/store_tests.rs
+++ b/beacon_node/beacon_chain/tests/store_tests.rs
@@ -5671,14 +5671,25 @@ async fn test_gloas_block_replay_with_envelopes() {
         !blocks_pending.is_empty(),
         "should have blocks for pending replay"
     );
-    // For Pending, no envelope for the last block; envelopes for intermediate blocks
-    // whose payloads are canonical.
-    let expected_pending_envelopes = blocks_pending.len().saturating_sub(1);
+    // For Pending, no envelope for the first block (slot 0) or last block; envelopes for
+    // intermediate blocks whose payloads are canonical.
+    let expected_pending_envelopes = blocks_pending.len().saturating_sub(2);
     assert_eq!(
         envelopes_pending.len(),
         expected_pending_envelopes,
         "pending replay should have envelopes for all blocks except the last"
     );
+    assert!(
+        blocks_pending
+            .iter()
+            .skip(1)
+            .take(envelopes_pending.len())
+            .map(|block| block.slot())
+            .eq(envelopes_pending
+                .iter()
+                .map(|envelope| envelope.message.slot)),
+        "block and envelope slots should match"
+    );
 
     // Load blocks for Full replay (envelopes for all blocks including the last).
     let (blocks_full, envelopes_full) = store
diff --git a/consensus/state_processing/src/block_replayer.rs b/consensus/state_processing/src/block_replayer.rs
index 22096293af..313a20da46 100644
--- a/consensus/state_processing/src/block_replayer.rs
+++ b/consensus/state_processing/src/block_replayer.rs
@@ -320,8 +320,8 @@ where
                         .block_hash;
 
                     // Similar to `is_parent_block_full`, but reading the block hash from the
-                    // not-yet-applied `block`.
-                    if block.is_parent_block_full(latest_bid_block_hash) {
+                    // not-yet-applied `block`. The 0x0 case covers genesis (no block replay reqd).
+                    if self.state.slot() != 0 && block.is_parent_block_full(latest_bid_block_hash) {
                         let envelope = next_envelope_at_slot(self.state.slot())?;
                         // State root for the next slot processing is now the envelope's state root.
                         self.apply_payload_envelope(&envelope, state_root)?