diff --git a/crates/trie/parallel/src/proof.rs b/crates/trie/parallel/src/proof.rs
index 8a45e0bf41cbb..1da1573b47a43 100644
--- a/crates/trie/parallel/src/proof.rs
+++ b/crates/trie/parallel/src/proof.rs
@@ -114,8 +114,8 @@ where
         );
         let storage_root_targets_len = storage_root_targets.len();
 
-        let num_threads = std::thread::available_parallelism()
-            .map_or(0, |num| num.get().saturating_sub(1).max(1));
+        let num_threads =
+            std::thread::available_parallelism().map_or(1, |num| (num.get() / 2).max(1));
 
         // create a local thread pool with a fixed number of workers
         let pool = rayon::ThreadPoolBuilder::new()