diff --git a/tensorflow/lite/model_builder.h b/tensorflow/lite/model_builder.h
index ed5e626a77b..01807103e1e 100644
--- a/tensorflow/lite/model_builder.h
+++ b/tensorflow/lite/model_builder.h
@@ -145,7 +145,7 @@ class FlatBufferModel {
   // lower-bound; ops in the graph may not have an associated runtime version,
   // in which case the actual required runtime might be greater than the
   // reported minimum.
-  string GetMinimumRuntime() const;
+  std::string GetMinimumRuntime() const;
 
   /// Returns true if the model identifier is correct (otherwise false and
   /// reports an error).