diff --git a/cpp/arcticdb/pipeline/read_frame.cpp b/cpp/arcticdb/pipeline/read_frame.cpp
index 4408334214..bfab7cdcb9 100644
--- a/cpp/arcticdb/pipeline/read_frame.cpp
+++ b/cpp/arcticdb/pipeline/read_frame.cpp
@@ -1013,7 +1013,7 @@ std::unique_ptr<StringReducer> get_string_reducer(
             const auto alloc_width = get_max_string_size_in_column(column.data().buffer(), context, frame, frame_field, slice_map, true);
             string_reducer = std::make_unique<UnicodeConvertingStringReducer>(column, context, frame, frame_field, alloc_width);
         } else {
-            const auto alloc_width = get_max_string_size_in_column(column.data().buffer(), context, frame, frame_field, slice_map, false);
+            const auto alloc_width = get_max_string_size_in_column(column.data().buffer(), context, frame, frame_field, slice_map, true);
             string_reducer = std::make_unique<FixedStringReducer>(column, context, frame, frame_field, alloc_width);
         }
     } else {