diff --git a/tools/db_stress.cc b/tools/db_stress.cc
index f291934ba..0b490746c 100644
--- a/tools/db_stress.cc
+++ b/tools/db_stress.cc
@@ -857,7 +857,7 @@ class SharedState {
             "Cannot use --expected_values_path on when "
             "--clear_column_family_one_in is greater than zero.");
       }
-      size_t size = 0;
+      uint64_t size = 0;
       if (status.ok()) {
         status = FLAGS_env->GetFileSize(FLAGS_expected_values_path, &size);
       }