diff --git a/src/app/ui/skin/skin_theme.cpp b/src/app/ui/skin/skin_theme.cpp
index 60656d638..84b8f424f 100644
--- a/src/app/ui/skin/skin_theme.cpp
+++ b/src/app/ui/skin/skin_theme.cpp
@@ -1567,8 +1567,8 @@ void SkinTheme::paintTextBox(ui::PaintEvent& ev)
   Graphics* g = ev.graphics();
   Widget* widget = static_cast<Widget*>(ev.getSource());
 
-  drawTextBox(g, widget, NULL, NULL,
-              BGCOLOR, colors.textboxText());
+  Theme::drawTextBox(g, widget, nullptr, nullptr,
+                     BGCOLOR, colors.textboxText());
 }
 
 void SkinTheme::paintView(PaintEvent& ev)
diff --git a/src/ui/intern.h b/src/ui/intern.h
index ecc5e092c..67d7bfbbc 100644
--- a/src/ui/intern.h
+++ b/src/ui/intern.h
@@ -1,5 +1,5 @@
 // Aseprite UI Library
-// Copyright (C) 2001-2013, 2015  David Capello
+// Copyright (C) 2001-2016  David Capello
 //
 // This file is released under the terms of the MIT license.
 // Read LICENSE.txt for more information.
@@ -36,11 +36,6 @@ namespace ui {
 
   } // namespace details
 
-  // theme.cpp
-
-  void drawTextBox(Graphics* g, Widget* textbox,
-                   int* w, int* h, gfx::Color bg, gfx::Color fg);
-
 } // namespace ui
 
 #endif
diff --git a/src/ui/textbox.cpp b/src/ui/textbox.cpp
index ded466bdb..fac13a1e0 100644
--- a/src/ui/textbox.cpp
+++ b/src/ui/textbox.cpp
@@ -156,7 +156,7 @@ void TextBox::onSizeHint(SizeHintEvent& ev)
   int w = 0;
   int h = 0;
 
-  drawTextBox(NULL, this, &w, &h, gfx::ColorNone, gfx::ColorNone);
+  Theme::drawTextBox(nullptr, this, &w, &h, gfx::ColorNone, gfx::ColorNone);
 
   if (this->align() & WORDWRAP) {
     View* view = View::getView(this);
@@ -170,7 +170,7 @@ void TextBox::onSizeHint(SizeHintEvent& ev)
     }
 
     w = MAX(min, width);
-    drawTextBox(NULL, this, &w, &h, gfx::ColorNone, gfx::ColorNone);
+    Theme::drawTextBox(nullptr, this, &w, &h, gfx::ColorNone, gfx::ColorNone);
 
     w = min;
   }
diff --git a/src/ui/theme.cpp b/src/ui/theme.cpp
index f30304d95..4bd151874 100644
--- a/src/ui/theme.cpp
+++ b/src/ui/theme.cpp
@@ -79,8 +79,9 @@ Theme* get_theme()
   return current_theme;
 }
 
-void drawTextBox(Graphics* g, Widget* widget,
-                 int* w, int* h, gfx::Color bg, gfx::Color fg)
+// static
+void Theme::drawTextBox(Graphics* g, Widget* widget,
+                        int* w, int* h, gfx::Color bg, gfx::Color fg)
 {
   View* view = View::getView(widget);
   char* text = const_cast<char*>(widget->text().c_str());
diff --git a/src/ui/theme.h b/src/ui/theme.h
index 6d3407ad4..1c3d4565c 100644
--- a/src/ui/theme.h
+++ b/src/ui/theme.h
@@ -8,6 +8,7 @@
 #define UI_THEME_H_INCLUDED
 #pragma once
 
+#include "gfx/color.h"
 #include "gfx/size.h"
 #include "ui/base.h"
 #include "ui/cursor_type.h"
@@ -23,6 +24,7 @@ namespace she {
 namespace ui {
 
   class Cursor;
+  class Graphics;
   class PaintEvent;
   class Widget;
 
@@ -72,6 +74,9 @@ namespace ui {
     virtual void paintPopupWindow(PaintEvent& ev) = 0;
     virtual void paintTooltip(PaintEvent& ev) = 0;
 
+    static  void drawTextBox(Graphics* g, Widget* textbox,
+                             int* w, int* h, gfx::Color bg, gfx::Color fg);
+
   protected:
     virtual void onRegenerate() = 0;