diff --git a/.changeset/twenty-years-type.md b/.changeset/twenty-years-type.md
new file mode 100644
index 00000000..d2d6fbf3
--- /dev/null
+++ b/.changeset/twenty-years-type.md
@@ -0,0 +1,6 @@
+---
+"@ckb-ccc/spore": patch
+---
+
+fix(spore): Ensure proper Transaction kept
+  
\ No newline at end of file
diff --git a/packages/spore/src/cobuild/index.ts b/packages/spore/src/cobuild/index.ts
index c1c5b52b..5c89c7a3 100644
--- a/packages/spore/src/cobuild/index.ts
+++ b/packages/spore/src/cobuild/index.ts
@@ -164,7 +164,7 @@ export async function prepareSporeTransaction(
   }
 
   const existedActions = extractCobuildActionsFromTx(tx);
-  tx = await signer.prepareTransaction(tx);
+  tx = ccc.Transaction.from(await signer.prepareTransaction(tx));
   injectCobuild(tx, [existedActions, actions].flat());
   return tx;
 }