diff --git a/tensorflow/lite/toco/model.h b/tensorflow/lite/toco/model.h
index 7a95e5db582..ff34269c465 100644
--- a/tensorflow/lite/toco/model.h
+++ b/tensorflow/lite/toco/model.h
@@ -21,6 +21,7 @@ limitations under the License.
 #include <memory>
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
 #include "absl/types/optional.h"