diff --git a/crates/trie/sparse/src/trie.rs b/crates/trie/sparse/src/trie.rs
index 0fa1fd9c66e..2a65d62dec9 100644
--- a/crates/trie/sparse/src/trie.rs
+++ b/crates/trie/sparse/src/trie.rs
@@ -437,7 +437,10 @@ impl SparseNode {
     /// Returns the memory size of this node in bytes.
     pub const fn memory_size(&self) -> usize {
         match self {
-            Self::Empty | Self::Branch { .. } => core::mem::size_of::<Self>(),
+            Self::Empty => core::mem::size_of::<Self>(),
+            Self::Branch { .. } => {
+                core::mem::size_of::<Self>() + core::mem::size_of::<[B256; 16]>()
+            }
             Self::Leaf { key, .. } | Self::Extension { key, .. } => {
                 core::mem::size_of::<Self>() + key.len()
             }