diff --git a/src/gui/BufferPane.cc b/src/gui/BufferPane.cc
index 8188b15..e446869 100644
--- a/src/gui/BufferPane.cc
+++ b/src/gui/BufferPane.cc
@@ -113,7 +113,7 @@ int BufferPane::screen_rows_below_line(const Buffer::Iterator & line)
     return rows;
 }
 
-int BufferPane::screen_rows_above_line(const Buffer::Iterator & line, std::list<std::pair<int, Buffer::Iterator>> backward_lines)
+int BufferPane::screen_rows_above_line(const Buffer::Iterator & line, std::list<std::pair<int, Buffer::Iterator>> & backward_lines)
 {
     Buffer::Iterator i = line;
     int rows = 0;
@@ -126,7 +126,7 @@ int BufferPane::screen_rows_above_line(const Buffer::Iterator & line, std::list<
     return rows;
 }
 
-int BufferPane::update_cursor_row(std::list<std::pair<int, Buffer::Iterator>> backward_lines)
+int BufferPane::update_cursor_row(std::list<std::pair<int, Buffer::Iterator>> & backward_lines)
 {
     Buffer::Iterator start_of_line = *m_iterator;
     start_of_line.go_start_of_line();
diff --git a/src/gui/BufferPane.h b/src/gui/BufferPane.h
index 7eb892a..46219da 100644
--- a/src/gui/BufferPane.h
+++ b/src/gui/BufferPane.h
@@ -38,8 +38,8 @@ protected:
     int rows_in_line(const Buffer::Iterator & start_of_line);
     int rows_in_line_with_iterator_offset(const Buffer::Iterator & start_of_line, const Buffer::Iterator & reference, int * iterator_row_offset);
     int screen_rows_below_line(const Buffer::Iterator & line);
-    int screen_rows_above_line(const Buffer::Iterator & line, std::list<std::pair<int, Buffer::Iterator>> backward_lines);
-    int update_cursor_row(std::list<std::pair<int, Buffer::Iterator>> backward_lines);
+    int screen_rows_above_line(const Buffer::Iterator & line, std::list<std::pair<int, Buffer::Iterator>> & backward_lines);
+    int update_cursor_row(std::list<std::pair<int, Buffer::Iterator>> & backward_lines);
     void walk_line(const Buffer::Iterator & start_of_line, std::function<void(int, int, int, int, const Buffer::Iterator &)> callback);
     int col_x(int col)
     {