diff --git a/packages/components/nodes/vectorstores/Faiss_Existing/Faiss_Existing.ts b/packages/components/nodes/vectorstores/Faiss_Existing/Faiss_Existing.ts
index 8c8d03a84d4..15d476d8c9b 100644
--- a/packages/components/nodes/vectorstores/Faiss_Existing/Faiss_Existing.ts
+++ b/packages/components/nodes/vectorstores/Faiss_Existing/Faiss_Existing.ts
@@ -2,6 +2,7 @@ import { INode, INodeData, INodeOutputsValue, INodeParams } from '../../../src/I
 import { FaissStore } from 'langchain/vectorstores/faiss'
 import { Embeddings } from 'langchain/embeddings/base'
 import { getBaseClasses } from '../../../src/utils'
+import { Document } from 'langchain/document'
 
 class Faiss_Existing_VectorStores implements INode {
     label: string
@@ -70,6 +71,23 @@ class Faiss_Existing_VectorStores implements INode {
 
         const vectorStore = await FaissStore.load(basePath, embeddings)
 
+        // Avoid illegal invocation error
+        vectorStore.similaritySearchVectorWithScore = async (query: number[], k: number) => {
+            const index = vectorStore.index
+
+            if (k > index.ntotal()) {
+                const total = index.ntotal()
+                console.warn(`k (${k}) is greater than the number of elements in the index (${total}), setting k to ${total}`)
+                k = total
+            }
+
+            const result = index.search(query, k)
+            return result.labels.map((id, index) => {
+                const uuid = vectorStore._mapping[id]
+                return [vectorStore.docstore.search(uuid), result.distances[index]] as [Document, number]
+            })
+        }
+
         if (output === 'retriever') {
             const retriever = vectorStore.asRetriever(k)
             return retriever
diff --git a/packages/components/nodes/vectorstores/Faiss_Upsert/Faiss_Upsert.ts b/packages/components/nodes/vectorstores/Faiss_Upsert/Faiss_Upsert.ts
index f56eccdfea9..c234a4f5324 100644
--- a/packages/components/nodes/vectorstores/Faiss_Upsert/Faiss_Upsert.ts
+++ b/packages/components/nodes/vectorstores/Faiss_Upsert/Faiss_Upsert.ts
@@ -86,6 +86,23 @@ class FaissUpsert_VectorStores implements INode {
         const vectorStore = await FaissStore.fromDocuments(finalDocs, embeddings)
         await vectorStore.save(basePath)
 
+        // Avoid illegal invocation error
+        vectorStore.similaritySearchVectorWithScore = async (query: number[], k: number) => {
+            const index = vectorStore.index
+
+            if (k > index.ntotal()) {
+                const total = index.ntotal()
+                console.warn(`k (${k}) is greater than the number of elements in the index (${total}), setting k to ${total}`)
+                k = total
+            }
+
+            const result = index.search(query, k)
+            return result.labels.map((id, index) => {
+                const uuid = vectorStore._mapping[id]
+                return [vectorStore.docstore.search(uuid), result.distances[index]] as [Document, number]
+            })
+        }
+
         if (output === 'retriever') {
             const retriever = vectorStore.asRetriever(k)
             return retriever
diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index fbb61b00a0d..23b5bdf483d 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -36,7 +36,6 @@ import {
     isSameOverrideConfig,
     replaceAllAPIKeys,
     isFlowValidForStream,
-    isVectorStoreFaiss,
     databaseEntities,
     getApiKey,
     transformToCredentialEntity,
@@ -911,7 +910,6 @@ export class App {
             const nodeModule = await import(nodeInstanceFilePath)
             const nodeInstance = new nodeModule.nodeClass()
 
-            isStreamValid = isStreamValid && !isVectorStoreFaiss(nodeToExecuteData)
             logger.debug(`[server]: Running ${nodeToExecuteData.label} (${nodeToExecuteData.id})`)
 
             if (nodeToExecuteData.instance) checkMemorySessionId(nodeToExecuteData.instance, chatId)
diff --git a/packages/server/src/utils/index.ts b/packages/server/src/utils/index.ts
index 788b7c0ecb4..9be269874e8 100644
--- a/packages/server/src/utils/index.ts
+++ b/packages/server/src/utils/index.ts
@@ -18,7 +18,7 @@ import {
     IComponentCredentials,
     ICredentialReqBody
 } from '../Interface'
-import { cloneDeep, get, omit, merge, isEqual } from 'lodash'
+import { cloneDeep, get, isEqual } from 'lodash'
 import {
     ICommonObject,
     getInputVariables,
@@ -393,25 +393,6 @@ export const getVariableValue = (
     return returnVal
 }
 
-/**
- * Temporarily disable streaming if vectorStore is Faiss
- * @param {INodeData} flowNodeData
- * @returns {boolean}
- */
-export const isVectorStoreFaiss = (flowNodeData: INodeData) => {
-    if (flowNodeData.inputs && flowNodeData.inputs.vectorStoreRetriever) {
-        const vectorStoreRetriever = flowNodeData.inputs.vectorStoreRetriever
-        if (typeof vectorStoreRetriever === 'string' && vectorStoreRetriever.includes('faiss')) return true
-        if (
-            typeof vectorStoreRetriever === 'object' &&
-            vectorStoreRetriever.vectorStore &&
-            vectorStoreRetriever.vectorStore.constructor.name === 'FaissStore'
-        )
-            return true
-    }
-    return false
-}
-
 /**
  * Loop through each inputs and resolve variable if neccessary
  * @param {INodeData} reactFlowNodeData
@@ -426,11 +407,6 @@ export const resolveVariables = (
     chatHistory: IMessage[]
 ): INodeData => {
     let flowNodeData = cloneDeep(reactFlowNodeData)
-    if (reactFlowNodeData.instance && isVectorStoreFaiss(reactFlowNodeData)) {
-        // omit and merge because cloneDeep of instance gives "Illegal invocation" Exception
-        const flowNodeDataWithoutInstance = cloneDeep(omit(reactFlowNodeData, ['instance']))
-        flowNodeData = merge(flowNodeDataWithoutInstance, { instance: reactFlowNodeData.instance })
-    }
     const types = 'inputs'
 
     const getParamValues = (paramsObj: ICommonObject) => {
@@ -819,7 +795,7 @@ export const isFlowValidForStream = (reactFlowNodes: IReactFlowNode[], endingNod
         isValidChainOrAgent = whitelistAgents.includes(endingNodeData.name)
     }
 
-    return isChatOrLLMsExist && isValidChainOrAgent && !isVectorStoreFaiss(endingNodeData)
+    return isChatOrLLMsExist && isValidChainOrAgent
 }
 
 /**