diff --git a/src/RefImplementations.cc b/src/RefImplementations.cc
index 83e6343af6..37a6df3f40 100644
--- a/src/RefImplementations.cc
+++ b/src/RefImplementations.cc
@@ -1234,6 +1234,11 @@ bool EmbeddingSpMDM_ref(
     int64_t current = 0;
 
     if (no_bag) {
+      // in edge cases, input_stride can be larger than output_stride, to make
+      // sure no memory overflow also be backward compatible, get the min value
+      // of input_stride and output_stride, and only copy the overlap part of
+      // data
+      auto copy_width = std::min(output_stride, input_stride);
       for (int m = 0; m < output_size; ++m) {
         int64_t idx = indices[m];
 
@@ -1242,7 +1247,7 @@ bool EmbeddingSpMDM_ref(
         }
         if constexpr (isOutput8bit) {
           const InType* input_row_ptr = input + input_stride * idx;
-          memcpy(out, input_row_ptr, sizeof(InType) * input_stride);
+          memcpy(out, input_row_ptr, sizeof(InType) * copy_width);
         } else {
           memset(buf.data(), 0, sizeof(float) * block_size);
           const float* scale_bias = reinterpret_cast<const float*>(