diff --git a/src/render/Render_abstract.cpp b/src/render/Render_abstract.cpp
index 0200efb8e05bc2821d7b6287e49d88e631b43bee..968dbf5e951b4004177543e9e20a384fbb399a3b 100644
--- a/src/render/Render_abstract.cpp
+++ b/src/render/Render_abstract.cpp
@@ -348,7 +348,7 @@ void Render_abstract::update_vertical_line(const Element_pos &line_position) {
     const std::map<long int, double>::const_iterator it_end = var_map.end();
     while (it != it_end) {
         draw_text_value((*it).first, (*it).second, -1);
-        it++;
+        ++it;
     }
 
     update_render();