diff --git a/src/page.h b/src/page.h
index e70e5eb..ff17c23 100644
--- a/src/page.h
+++ b/src/page.h
@@ -696,7 +696,7 @@ public:
             uint64_t mixin_no = 0;
 
             if (!mixin_numbers.empty())
-                mixin_numbers.at(0) - 1;
+                mixin_no = mixin_numbers.at(0) - 1;
 
             // set output page template map
             txs.push_back(mstch::map {
diff --git a/src/tools.cpp b/src/tools.cpp
index 13332db..cc70900 100644
--- a/src/tools.cpp
+++ b/src/tools.cpp
@@ -509,9 +509,25 @@ get_mixin_no(const string& json_str)
 {
     vector<uint64_t> mixin_no;
 
+    json j;
+
+    try
+    {
+        j = json::parse(json_str);
+
+        mixin_no.push_back(j["vin"].at(0)["key"]["key_offsets"].size());
+    }
+    catch (std::invalid_argument& e)
+    {
+        cerr << "get_mixin_no: " << e.what() << endl;
+        return mixin_no;
+    }
+
     return mixin_no;
 }
 
+
+
 vector<uint64_t>
 get_mixin_no_in_txs(const vector<transaction>& txs)
 {