diff --git a/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs b/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
index 0df2fc1a1bf..9a18b3336eb 100644
--- a/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
+++ b/beacon_node/lighthouse_network/src/rpc/codec/ssz_snappy.rs
@@ -618,7 +618,7 @@ mod tests {
     use std::sync::Arc;
     use types::{
         BeaconBlock, BeaconBlockAltair, BeaconBlockBase, BeaconBlockMerge, Epoch, ForkContext,
-        Hash256, Signature, SignedBeaconBlock, Slot,
+        FullPayload, Hash256, Signature, SignedBeaconBlock, Slot,
     };
 
     use snap::write::FrameEncoder;
@@ -656,11 +656,12 @@ mod tests {
 
     /// Merge block with length < max_rpc_size.
     fn merge_block_small(fork_context: &ForkContext) -> SignedBeaconBlock<Spec> {
-        let mut block = BeaconBlockMerge::empty(&Spec::default_spec());
+        let mut block: BeaconBlockMerge<_, FullPayload<Spec>> =
+            BeaconBlockMerge::empty(&Spec::default_spec());
         let tx = VariableList::from(vec![0; 1024]);
         let txs = VariableList::from(std::iter::repeat(tx).take(100).collect::<Vec<_>>());
 
-        block.body.execution_payload.transactions = txs;
+        block.body.execution_payload.execution_payload.transactions = txs;
 
         let block = BeaconBlock::Merge(block);
         assert!(block.ssz_bytes_len() <= max_rpc_size(fork_context));
@@ -671,11 +672,12 @@ mod tests {
     /// The max limit for a merge block is in the order of ~16GiB which wouldn't fit in memory.
     /// Hence, we generate a merge block just greater than `MAX_RPC_SIZE` to test rejection on the rpc layer.
     fn merge_block_large(fork_context: &ForkContext) -> SignedBeaconBlock<Spec> {
-        let mut block = BeaconBlockMerge::empty(&Spec::default_spec());
+        let mut block: BeaconBlockMerge<_, FullPayload<Spec>> =
+            BeaconBlockMerge::empty(&Spec::default_spec());
         let tx = VariableList::from(vec![0; 1024]);
         let txs = VariableList::from(std::iter::repeat(tx).take(100000).collect::<Vec<_>>());
 
-        block.body.execution_payload.transactions = txs;
+        block.body.execution_payload.execution_payload.transactions = txs;
 
         let block = BeaconBlock::Merge(block);
         assert!(block.ssz_bytes_len() > max_rpc_size(fork_context));
diff --git a/beacon_node/lighthouse_network/src/rpc/protocol.rs b/beacon_node/lighthouse_network/src/rpc/protocol.rs
index 8898d774125..c0431253735 100644
--- a/beacon_node/lighthouse_network/src/rpc/protocol.rs
+++ b/beacon_node/lighthouse_network/src/rpc/protocol.rs
@@ -66,15 +66,10 @@ lazy_static! {
     /// Note: This is only the theoretical upper bound. We further bound the max size we receive over the network
     /// with `MAX_RPC_SIZE_POST_MERGE`.
     pub static ref SIGNED_BEACON_BLOCK_MERGE_MAX: usize =
-    // Size of a full merge block with an empty execution payload
-    SignedBeaconBlock::<MainnetEthSpec>::from_block(
-        BeaconBlock::Merge(BeaconBlockMerge::<MainnetEthSpec>::full(&MainnetEthSpec::default_spec())),
-        Signature::empty(),
-    )
-    .as_ssz_bytes()
-    .len()
-    - types::ExecutionPayload::<MainnetEthSpec>::empty().as_ssz_bytes().len() // subtracting size of empty execution payload included above
-    + types::ExecutionPayload::<MainnetEthSpec>::max_execution_payload_size(); // adding max size of execution payload (~16gb)
+    // Size of a full altair block
+    *SIGNED_BEACON_BLOCK_ALTAIR_MAX
+    + types::ExecutionPayload::<MainnetEthSpec>::max_execution_payload_size() // adding max size of execution payload (~16gb)
+    + ssz::BYTES_PER_LENGTH_OFFSET; // Adding the additional ssz offset for the `ExecutionPayload` field
 
     pub static ref BLOCKS_BY_ROOT_REQUEST_MIN: usize =
         VariableList::<Hash256, MaxRequestBlocks>::from(Vec::<Hash256>::new())