diff --git a/src/core/KnownTags.ts b/src/core/KnownTags.ts
index d9809630..70f66905 100644
--- a/src/core/KnownTags.ts
+++ b/src/core/KnownTags.ts
@@ -36,6 +36,7 @@ export const WARP_TAGS = {
   WASM_META: 'Wasm-Meta',
   REQUEST_VRF: 'Request-Vrf',
   SIGNATURE_TYPE: 'Signature-Type',
+  UPLOADER_TX_ID: 'Uploader-Tx-Id',
   WARP_TESTNET: 'Warp-Testnet',
   MANIFEST: 'Contract-Manifest',
   NONCE: 'Nonce'
diff --git a/src/core/modules/impl/ArweaveGQLTxsFetcher.ts b/src/core/modules/impl/ArweaveGQLTxsFetcher.ts
index 1a286b30..ff5dcc5d 100644
--- a/src/core/modules/impl/ArweaveGQLTxsFetcher.ts
+++ b/src/core/modules/impl/ArweaveGQLTxsFetcher.ts
@@ -4,6 +4,7 @@ import { ArweaveWrapper } from '../../../utils/ArweaveWrapper';
 import { sleep } from '../../../utils/utils';
 import { Benchmark } from '../../../logging/Benchmark';
 import { Warp } from '../../Warp';
+import { WARP_TAGS } from '../../KnownTags';
 
 const TRANSACTIONS_QUERY = `query Transactions($tags: [TagFilter!]!, $blockFilter: BlockFilter!, $first: Int!, $after: String) {
     transactions(tags: $tags, block: $blockFilter, first: $first, sort: HEIGHT_ASC, after: $after) {
@@ -56,6 +57,33 @@ const TRANSACTION_QUERY = `query Transaction($id: ID!) {
         }
 }`;
 
+// this is a query for old/legacy bundler format
+const TRANSACTION_QUERY_USING_TAG = `query Transactions($tags: [TagFilter!]!) {
+  transactions(tags: $tags) {
+      edges {
+        node {
+          id
+          owner { address, key }
+          recipient
+          tags {
+            name
+            value
+          }
+          block {
+            height
+            id
+            timestamp
+          }
+          fee { winston, ar }
+          quantity { winston, ar }
+          parent { id }
+          bundledIn { id }
+          signature
+        }
+      }
+  }
+}`;
+
 interface TagFilter {
   name: string;
   values: string[];
@@ -93,6 +121,23 @@ export class ArweaveGQLTxsFetcher {
     return response.transaction;
   }
 
+  /**
+   * Fetches transaction stored using legacy bundling format.
+   */
+  async transactionUsingUploaderTag(transactionId: string): Promise<GQLTransaction> {
+    const txTag: TagFilter = {
+      name: WARP_TAGS.UPLOADER_TX_ID,
+      values: [transactionId]
+    };
+    const response = (await this.fetch<GQLResultInterface['data']>(TRANSACTION_QUERY_USING_TAG, { tags: [txTag] }))
+      .transactions;
+
+    if (response.edges.length < 1) {
+      throw new Error(`No interaction with tag ${WARP_TAGS.UPLOADER_TX_ID}:${transactionId}`);
+    }
+    return response.edges[0].node;
+  }
+
   async transactions(variables: ArweaveTransactionQuery): Promise<GQLEdgeInterface[]> {
     let pageResult = (await this.fetch<GQLResultInterface['data']>(TRANSACTIONS_QUERY, variables)).transactions;
     const edges: GQLEdgeInterface[] = [...pageResult.edges];
diff --git a/src/core/modules/impl/ArweaveGatewayBundledContractDefinitionLoader.ts b/src/core/modules/impl/ArweaveGatewayBundledContractDefinitionLoader.ts
index 2c501b6d..ee88d412 100644
--- a/src/core/modules/impl/ArweaveGatewayBundledContractDefinitionLoader.ts
+++ b/src/core/modules/impl/ArweaveGatewayBundledContractDefinitionLoader.ts
@@ -17,6 +17,7 @@ import { DefinitionLoader } from '../DefinitionLoader';
 import { GW_TYPE } from '../InteractionsLoader';
 import { ArweaveGQLTxsFetcher } from './ArweaveGQLTxsFetcher';
 import { WasmSrc } from './wasm/WasmSrc';
+import Arweave from 'arweave';
 
 function getTagValue(tags: GQLTagInterface[], tagName: string, orDefault = undefined) {
   const tag = tags.find(({ name }) => name === tagName);
@@ -32,7 +33,7 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
 
   async load<State>(contractTxId: string, evolvedSrcTxId?: string): Promise<ContractDefinition<State>> {
     const benchmark = Benchmark.measure();
-    const contractTx = await this.arweaveTransactions.transaction(contractTxId);
+    const contractTx: GQLTransaction = await this.fetchContractTx(contractTxId);
     this.logger.debug('Contract tx fetch time', benchmark.elapsed());
     const owner = contractTx.owner.address;
 
@@ -85,6 +86,14 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
     return contractDefinition;
   }
 
+  async fetchContractTx(contractTxId: string): Promise<GQLTransaction | null> {
+    const txUsingId = await this.arweaveTransactions.transaction(contractTxId);
+    if (txUsingId == null) {
+      return await this.arweaveTransactions.transactionUsingUploaderTag(contractTxId);
+    }
+    return txUsingId;
+  }
+
   private async convertToWarpCompatibleContractTx(gqlTransaction: GQLTransaction) {
     const tags = gqlTransaction.tags.map(({ name, value }) => ({
       name: Buffer.from(name).toString('base64url'),
@@ -103,7 +112,7 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
   async loadContractSource(srcTxId: string): Promise<ContractSource> {
     const benchmark = Benchmark.measure();
 
-    const contractSrcTx = await this.arweaveTransactions.transaction(srcTxId);
+    const contractSrcTx = await this.fetchContractTx(srcTxId);
     const srcContentType = getTagValue(contractSrcTx.tags, SMART_WEAVE_TAGS.CONTENT_TYPE);
 
     if (!SUPPORTED_SRC_CONTENT_TYPES.includes(srcContentType)) {
@@ -112,10 +121,7 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
 
     const contractType: ContractType = srcContentType === 'application/javascript' ? 'js' : 'wasm';
 
-    const src =
-      contractType === 'js'
-        ? await this.arweaveWrapper.txDataString(srcTxId)
-        : await this.arweaveWrapper.txData(srcTxId);
+    const src = await this.contractSource(contractSrcTx, contractType);
 
     let srcWasmLang: string | undefined;
     let wasmSrc: WasmSrc;
@@ -124,7 +130,7 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
       wasmSrc = new WasmSrc(src as Buffer);
       srcWasmLang = getTagValue(contractSrcTx.tags, WARP_TAGS.WASM_LANG);
       if (!srcWasmLang) {
-        throw new Error(`Wasm lang not set for wasm contract src ${srcTxId}`);
+        throw new Error(`Wasm lang not set for wasm contract src ${contractSrcTx.id}`);
       }
       srcMetaData = JSON.parse(getTagValue(contractSrcTx.tags, WARP_TAGS.WASM_META));
     }
@@ -142,6 +148,22 @@ export class ArweaveGatewayBundledContractDefinitionLoader implements Definition
     };
   }
 
+  private async contractSource(contractSrcTx: GQLTransaction, contractType: ContractType): Promise<string | Buffer> {
+    const uploaderId = getTagValue(contractSrcTx.tags, WARP_TAGS.UPLOADER_TX_ID);
+
+    if (uploaderId != null) {
+      const txString = await this.arweaveWrapper.txDataString(contractSrcTx.id);
+      if (contractType === 'wasm') {
+        throw new Error('WASM contracts in legacy format are not supported using AR GW');
+      }
+      return Arweave.utils.b64UrlToString(JSON.parse(txString).data);
+    }
+
+    return contractType === 'js'
+      ? await this.arweaveWrapper.txDataString(contractSrcTx.id)
+      : await this.arweaveWrapper.txData(contractSrcTx.id);
+  }
+
   private async evalInitialState(contractTx: GQLTransaction): Promise<string> {
     if (getTagValue(contractTx.tags, WARP_TAGS.INIT_STATE)) {
       return getTagValue(contractTx.tags, WARP_TAGS.INIT_STATE);