diff --git a/extension/flat_tensor/flat_tensor_data_map.cpp b/extension/flat_tensor/flat_tensor_data_map.cpp
index ff526e359d4..bf54ae014b5 100644
--- a/extension/flat_tensor/flat_tensor_data_map.cpp
+++ b/extension/flat_tensor/flat_tensor_data_map.cpp
@@ -141,7 +141,7 @@ ET_NODISCARD Result<FreeableBuffer> FlatTensorDataMap::get_data(
       DataLoader::SegmentInfo(DataLoader::SegmentInfo::Type::External));
 }
 
-ET_NODISCARD Result<size_t> FlatTensorDataMap::load_data_into(
+ET_NODISCARD Error FlatTensorDataMap::load_data_into(
     ET_UNUSED const char* key,
     ET_UNUSED void* buffer,
     ET_UNUSED size_t size) const {
@@ -156,7 +156,7 @@ ET_NODISCARD Result<size_t> FlatTensorDataMap::load_data_into(
     return tensor_layout.error();
   }
   ET_CHECK_OR_RETURN_ERROR(
-      size < tensor_layout.get().nbytes(),
+      size <= tensor_layout.get().nbytes(),
       InvalidArgument,
       "Buffer size %zu is smaller than tensor size %zu",
       size,
@@ -187,6 +187,7 @@ ET_NODISCARD Result<const char*> FlatTensorDataMap::get_key(
   if (index < 0 || index >= flat_tensor_->tensors()->size()) {
     return Error::InvalidArgument;
   }
+
   return flat_tensor_->tensors()->Get(index)->fully_qualified_name()->c_str();
 }
 
diff --git a/extension/flat_tensor/flat_tensor_data_map.h b/extension/flat_tensor/flat_tensor_data_map.h
index 00f4bf07d19..972a5fa9c55 100644
--- a/extension/flat_tensor/flat_tensor_data_map.h
+++ b/extension/flat_tensor/flat_tensor_data_map.h
@@ -75,7 +75,7 @@ class FlatTensorDataMap final : public executorch::runtime::NamedDataMap {
    *
    * @returns an Error indicating if the load was successful.
    */
-  ET_NODISCARD executorch::runtime::Result<size_t>
+  ET_NODISCARD executorch::runtime::Error
   load_data_into(const char* key, void* buffer, size_t size) const override;
 
   /**
diff --git a/extension/flat_tensor/test/flat_tensor_data_map_test.cpp b/extension/flat_tensor/test/flat_tensor_data_map_test.cpp
index 681bc39a129..ac4583eda88 100644
--- a/extension/flat_tensor/test/flat_tensor_data_map_test.cpp
+++ b/extension/flat_tensor/test/flat_tensor_data_map_test.cpp
@@ -137,3 +137,26 @@ TEST_F(FlatTensorDataMapTest, FlatTensorDataMap_Keys) {
   Result<const char*> key2_res = data_map->get_key(2);
   EXPECT_EQ(key2_res.error(), Error::InvalidArgument);
 }
+
+TEST_F(FlatTensorDataMapTest, FlatTensorDataMap_LoadInto) {
+  Result<FlatTensorDataMap> data_map =
+      FlatTensorDataMap::load(data_map_loader_.get());
+  EXPECT_EQ(data_map.error(), Error::Ok);
+
+  // get the metadata
+  auto meta_data_res = data_map->get_metadata("a");
+  ASSERT_EQ(meta_data_res.error(), Error::Ok);
+
+  // get data blob
+  void* data = malloc(meta_data_res->nbytes());
+  auto load_into_error =
+      data_map->load_data_into("a", data, meta_data_res->nbytes());
+  ASSERT_EQ(load_into_error, Error::Ok);
+
+  // Check tensor data is correct.
+  float* data_a = static_cast<float*>(data);
+  for (int i = 0; i < 4; i++) {
+    EXPECT_EQ(data_a[i], 3.0);
+  }
+  free(data);
+}
diff --git a/runtime/core/named_data_map.h b/runtime/core/named_data_map.h
index 68639ed872a..ef5e413db67 100644
--- a/runtime/core/named_data_map.h
+++ b/runtime/core/named_data_map.h
@@ -53,10 +53,9 @@ class ET_EXPERIMENTAL NamedDataMap {
    * size of the data for a given key.
    * @param buffer The buffer to load the data into. Must point to at least
    * `size` bytes of memory.
-   * @return Result containing the number of bytes written on success. This will
-   * fail if the buffer is too small.
+   * @returns an Error indicating if the load was successful.
    */
-  ET_NODISCARD virtual Result<size_t>
+  ET_NODISCARD virtual Error
   load_data_into(const char* key, void* buffer, size_t size) const = 0;
 
   /**
diff --git a/runtime/executor/tensor_parser_exec_aten.cpp b/runtime/executor/tensor_parser_exec_aten.cpp
index a1ac245acca..66202acabc3 100644
--- a/runtime/executor/tensor_parser_exec_aten.cpp
+++ b/runtime/executor/tensor_parser_exec_aten.cpp
@@ -224,17 +224,12 @@ ET_NODISCARD Result<void*> getTensorDataPtr(
       if (!planned_ptr.ok()) {
         return planned_ptr.error();
       }
-      auto size =
+      auto load_error =
           named_data_map->load_data_into(fqn, planned_ptr.get(), nbytes);
-      if (size.error() != Error::Ok) {
-        return size.error();
+      if (load_error != Error::Ok) {
+        return load_error;
       }
-      ET_CHECK_OR_RETURN_ERROR(
-          size.get() == nbytes,
-          InvalidExternalData,
-          "Expected to load %zu bytes, actually loaded %u bytes",
-          nbytes,
-          static_cast<unsigned int>(size.get()));
+
       return planned_ptr;
     }
   }