diff --git a/package.json b/package.json
index 844ee970..cbc7c222 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@opensea/seaport-js",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "[Seaport](https://github.com/ProjectOpenSea/seaport) is a new marketplace protocol for safely and efficiently buying and selling NFTs. This is a JavaScript library intended to make interfacing with the contract reasonable and easy.",
   "license": "MIT",
   "author": "OpenSea Developers",
diff --git a/src/seaport.ts b/src/seaport.ts
index 4335f2a1..ec62d812 100644
--- a/src/seaport.ts
+++ b/src/seaport.ts
@@ -100,6 +100,9 @@ export class Seaport {
       providerOrSigner instanceof providers.Provider
         ? providerOrSigner
         : providerOrSigner.provider;
+    this.signer = (providerOrSigner as Signer)._isSigner
+      ? (providerOrSigner as Signer)
+      : undefined;
 
     if (!provider) {
       throw new Error(