diff --git a/packages/protocol-sdk/src/premint/premint-client.ts b/packages/protocol-sdk/src/premint/premint-client.ts
index 790e58a9e..6009a5cbb 100644
--- a/packages/protocol-sdk/src/premint/premint-client.ts
+++ b/packages/protocol-sdk/src/premint/premint-client.ts
@@ -14,7 +14,11 @@ import {
   zoraCreator1155PremintExecutorImplAddress,
   zoraCreatorFixedPriceSaleStrategyAddress,
 } from "@zoralabs/protocol-deployments";
-import { PremintConfig, preminterTypedDataDefinition } from "./preminter";
+import {
+  PremintConfig,
+  isValidSignatureV1,
+  preminterTypedDataDefinition,
+} from "./preminter";
 import type {
   PremintSignatureGetResponse,
   PremintSignatureResponse,
@@ -495,24 +499,20 @@ class PremintClient extends ClientBase {
     publicClient?: PublicClient;
   }): Promise<{
     isValid: boolean;
-    contractAddress: Address;
-    recoveredSigner: Address;
+    recoveredSigner: Address | undefined;
   }> {
     publicClient = this.getPublicClient(publicClient);
 
-    const [isValid, contractAddress, recoveredSigner] =
-      await publicClient.readContract({
-        abi: zoraCreator1155PremintExecutorImplABI,
-        address: this.getExecutorAddress(),
-        functionName: "isValidSignature",
-        args: [
-          convertCollection(data.collection),
-          convertPremint(data.premint),
-          data.signature as Hex,
-        ],
-      });
+    const { isAuthorized, recoveredAddress } = await isValidSignatureV1({
+      contractAddress: data.collection_address as Address,
+      chainId: this.chain.id,
+      originalContractAdmin: data.collection.contractAdmin as Address,
+      premintConfig: convertPremint(data.premint),
+      publicClient: this.getPublicClient(),
+      signature: data.signature as Hex,
+    });
 
-    return { isValid, contractAddress, recoveredSigner };
+    return { isValid: isAuthorized, recoveredSigner: recoveredAddress };
   }
 
   protected makeUrls({