diff --git a/operators/tokenizer/bpe_tokenizer_model.hpp b/operators/tokenizer/bpe_tokenizer_model.hpp
index cd6f03f7..e4a1e7c8 100644
--- a/operators/tokenizer/bpe_tokenizer_model.hpp
+++ b/operators/tokenizer/bpe_tokenizer_model.hpp
@@ -145,23 +145,32 @@ class BpeModel {
     uint32_t index = 0;
     auto merge_item = merges_json.begin();
     while (merge_item != merges_json.end()) {
-      std::string line = merge_item.value();
-      line.erase(std::remove(line.begin(), line.end(), '\r'), line.end());
-      if (line.empty()) continue;
-      if ((line[0] == '#') && (index == 0)) continue;
-      auto pos = line.find(' ');
-      if (pos == std::string::npos) {
-        return {
-            kOrtxErrorCorruptData,
-            "Cannot know how to parse line: " + line,
-        };
+      std::string w1, w2;
+      if (merge_item->is_string()) {
+        std::string line = merge_item.value();
+        line.erase(std::remove(line.begin(), line.end(), '\r'), line.end());
+        if (line.empty()) continue;
+        if ((line[0] == '#') && (index == 0)) continue;
+        auto pos = line.find(' ');
+        if (pos == std::string::npos) {
+          return {
+              kOrtxErrorCorruptData,
+              "Cannot know how to parse line: " + line,
+          };
+        }
+        w1 = line.substr(0, pos);
+        w2 = line.substr(pos + 1);
+      } else if (merge_item->is_array()) {
+        w1 = merge_item->at(0).get<std::string>();
+        w2 = merge_item->at(1).get<std::string>();
+      } else {
+        return {kOrtxErrorCorruptData, "Cannot know how to parse line: " + merge_item->dump()};
       }
-      std::string w1 = line.substr(0, pos);
-      std::string w2 = line.substr(pos + 1);
       int token_length = ort_extensions::narrow<int>(w1.length() + w2.length());
       if (w2.find("</w>") != std::string::npos || w1.find("</w>") != std::string::npos) {
         token_length -= 4;
       }
+
       auto iw1 = GetTokenId(w1);
       auto iw2 = GetTokenId(w2);
       auto iww = GetTokenId(w1 + w2);
diff --git a/operators/tokenizer/ugm_kernels.hpp b/operators/tokenizer/ugm_kernels.hpp
index dc19f37b..703c683d 100644
--- a/operators/tokenizer/ugm_kernels.hpp
+++ b/operators/tokenizer/ugm_kernels.hpp
@@ -18,6 +18,7 @@
 #include "op_def_struct.h"
 #include "base64.h"
 #include "ustring.h"
+#include "narrow.h"
 #include "nlohmann/json.hpp"
 #include "trietree.hpp"
 #include "tokenizer_jsconfig.hpp"
@@ -485,7 +486,7 @@ class SpmUgmDecoder {
       std::copy(ids_dim.begin(), ids_dim.begin() + ids_dim.size() - 1, output_dim.begin());
     }
 
-    size_t seq_len = ids_dim.back();
+    int64_t seq_len = ids_dim.back();
     size_t string_batch = ids.NumberOfElement() / seq_len;
 
     std::vector<std::string> decoded_strings;
@@ -495,7 +496,7 @@ class SpmUgmDecoder {
       std::string text;
       for (int64_t i = 0; i < seq_len; ++i) {
         std::string token;
-        Id2Token(p_ids[i], token, nullptr);
+        Id2Token(ort_extensions::narrow<extTokenId_t>(p_ids[i]), token, nullptr);
         if (token.find(spm_escaped_space) == 0) {
           token = ws + token.substr(spm_escaped_space.length());
         }
@@ -508,6 +509,7 @@ class SpmUgmDecoder {
           text = text.substr(1);
         }
       }
+
       decoded_strings.push_back(text);
     }