diff --git a/yarn-project/pxe/src/contract_function_simulator/pxe_oracle_interface.ts b/yarn-project/pxe/src/contract_function_simulator/pxe_oracle_interface.ts
index ac081286b970..f53a5e4f0a04 100644
--- a/yarn-project/pxe/src/contract_function_simulator/pxe_oracle_interface.ts
+++ b/yarn-project/pxe/src/contract_function_simulator/pxe_oracle_interface.ts
@@ -641,12 +641,13 @@ export class PXEOracleInterface implements ExecutionDataProvider {
     const siloedNullifier = await siloNullifier(contractAddress, nullifier);
 
     // We store notes by their index in the global note hash tree, which has the convenient side effect of validating
-    // note existence in said tree.
-    const [uniqueNoteHashTreeIndexInBlock] = await this.aztecNode.findLeavesIndexes(
-      syncedBlockNumber,
-      MerkleTreeId.NOTE_HASH_TREE,
-      [uniqueNoteHash],
-    );
+    // note existence in said tree. We concurrently also check if the note's nullifier exists, performing all node
+    // queries in a single round-trip.
+    const [[uniqueNoteHashTreeIndexInBlock], [nullifierIndex]] = await Promise.all([
+      this.aztecNode.findLeavesIndexes(syncedBlockNumber, MerkleTreeId.NOTE_HASH_TREE, [uniqueNoteHash]),
+      this.aztecNode.findLeavesIndexes(syncedBlockNumber, MerkleTreeId.NULLIFIER_TREE, [siloedNullifier]),
+    ]);
+
     if (uniqueNoteHashTreeIndexInBlock === undefined) {
       throw new Error(
         `Note hash ${noteHash} (uniqued as ${uniqueNoteHash}) is not present on the tree at block ${syncedBlockNumber} (from tx ${txHash})`,
@@ -676,9 +677,6 @@ export class PXEOracleInterface implements ExecutionDataProvider {
       nullifier: noteDao.siloedNullifier.toString(),
     });
 
-    const [nullifierIndex] = await this.aztecNode.findLeavesIndexes(syncedBlockNumber, MerkleTreeId.NULLIFIER_TREE, [
-      siloedNullifier,
-    ]);
     if (nullifierIndex !== undefined) {
       const { data: _, ...blockHashAndNum } = nullifierIndex;
       await this.noteDataProvider.removeNullifiedNotes([{ data: siloedNullifier, ...blockHashAndNum }], recipient);