diff --git a/src/appleseed.studio/mainwindow/rendering/lightpathslayer.cpp b/src/appleseed.studio/mainwindow/rendering/lightpathslayer.cpp
index f8a527d876..5984dc1032 100644
--- a/src/appleseed.studio/mainwindow/rendering/lightpathslayer.cpp
+++ b/src/appleseed.studio/mainwindow/rendering/lightpathslayer.cpp
@@ -45,8 +45,8 @@
 #include "foundation/image/color.h"
 #include "foundation/image/colorspace.h"
 #include "foundation/math/scalar.h"
+#include "foundation/string/string.h"
 #include "foundation/utility/api/apistring.h"
-#include "foundation/utility/string.h"
 
 // Qt headers.
 #include <QKeyEvent>
diff --git a/src/appleseed.studio/mainwindow/rendering/lightpathsmanager.cpp b/src/appleseed.studio/mainwindow/rendering/lightpathsmanager.cpp
index 6fa644bd8f..e92780e57e 100644
--- a/src/appleseed.studio/mainwindow/rendering/lightpathsmanager.cpp
+++ b/src/appleseed.studio/mainwindow/rendering/lightpathsmanager.cpp
@@ -47,7 +47,7 @@
 #include "foundation/image/canvasproperties.h"
 #include "foundation/image/image.h"
 #include "foundation/math/vector.h"
-#include "foundation/utility/string.h"
+#include "foundation/string/string.h"
 
 // Qt headers.
 #include <QEvent>
diff --git a/src/appleseed.studio/mainwindow/rendering/qttilecallback.cpp b/src/appleseed.studio/mainwindow/rendering/qttilecallback.cpp
index e744c240ec..ac87f498b1 100644
--- a/src/appleseed.studio/mainwindow/rendering/qttilecallback.cpp
+++ b/src/appleseed.studio/mainwindow/rendering/qttilecallback.cpp
@@ -82,9 +82,8 @@ namespace
             const size_t    thread_index,
             const size_t    thread_count) override
         {
-            assert(m_render_widget);
-            m_render_widget->highlight_tile(*frame, tile_x, tile_y, thread_index, thread_count);
-
+            assert(m_render_layer);
+            m_render_layer->highlight_tile(*frame, tile_x, tile_y, thread_index, thread_count);
             emit signal_update();
         }