diff --git a/CHANGES b/CHANGES
index a7815f8e2..a6a0b1474 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,8 @@ CHANGES IN FLTK 1.1.8
 	- Documentation fixes (STR #1454, STR #1455, STR #1456,
 	  STR #1457, STR #1458, STR #1460, STR #1481, STR #1578,
 	  STR #1639, STR #1645, STR #1644, STR #1792, STR #1793)
+	- Changing the window size in FLUID would not mark the 
+	  project as modified (STR #1751)
 	- Fixed fl_filename_isdir for "/"-path (STR #1761)
 	- Fixed Fl_Chart drawing (STR #1756)
 	- Fixed mapping of subwindows with unmapped parent
diff --git a/fluid/Fl_Window_Type.cxx b/fluid/Fl_Window_Type.cxx
index dcd31e499..a52d47d0c 100644
--- a/fluid/Fl_Window_Type.cxx
+++ b/fluid/Fl_Window_Type.cxx
@@ -503,6 +503,7 @@ void Overlay_Window::resize(int X,int Y,int W,int H) {
   Fl_Widget* t = resizable(); resizable(0);
   Fl_Overlay_Window::resize(X,Y,W,H);
   resizable(t);
+  set_modflag(1);
   update_xywh();
 }