diff --git a/crates/optimism/node/src/node.rs b/crates/optimism/node/src/node.rs
index 68429bc290f0..4b5cbe9156e9 100644
--- a/crates/optimism/node/src/node.rs
+++ b/crates/optimism/node/src/node.rs
@@ -232,7 +232,7 @@ where
         let debug_ext = OpDebugWitnessApi::new(
             ctx.node.provider().clone(),
             ctx.node.evm_config().clone(),
-            Box::new(ctx.task_executor().clone()),
+            Box::new(ctx.node.task_executor().clone()),
         );
 
         self.0
diff --git a/crates/optimism/rpc/src/witness.rs b/crates/optimism/rpc/src/witness.rs
index 63bd45af9877..1d7b83bd4b45 100644
--- a/crates/optimism/rpc/src/witness.rs
+++ b/crates/optimism/rpc/src/witness.rs
@@ -68,10 +68,20 @@ where
         let _permit = self.inner.semaphore.acquire().await;
 
         let parent_header = self.parent_header(parent_block_hash).to_rpc_result()?;
+
+        let provider = self.inner.provider.clone();
+        let builder = self.inner.builder.clone();
+
+        // Spawn the CPU-intensive work on a blocking task
         self.inner
-            .builder
-            .payload_witness(&self.inner.provider, parent_header, attributes)
-            .map_err(|err| internal_rpc_err(err.to_string()))
+            .task_spawner
+            .spawn_blocking(move || {
+                builder
+                    .payload_witness(&provider, parent_header, attributes)
+                    .map_err(|err| internal_rpc_err(err.to_string()))
+            })
+            .await
+            .map_err(|err| internal_rpc_err(err.to_string()))?
     }
 }