diff --git a/include/printer.cpp b/include/printer.cpp
index 5eacafcbd..56d184b22 100755
--- a/include/printer.cpp
+++ b/include/printer.cpp
@@ -2204,25 +2204,30 @@ BOOLEAN XVT_CALLCONV1 calc_font_callback(long data)
   // Create pint window
   WINDOW win = xvt_print_create_win(printer().get_printrcd(), "Calcolo font");
   
-  // Set print font
-  xvt_set_font(win, fd._name, XVT_FS_NONE, fd._size);
+  if (win != NULL_WIN)
+  {
+  	long pw, ph, phr, pvr; // Printer width, height, horizontal and vertical resolution
+  	xvt_app_escape (XVT_ESC_GET_PRINTER_INFO, printer().get_printrcd(), &ph, &pw, &pvr, &phr);
+	
+		TString test(fd._columns);
+		test.fill('M', fd._columns);
+		for (int size = fd._size; size > 0; size--)
+		{
+	  	// Set print font
+	  	xvt_set_font(win, fd._name, XVT_FS_NONE, size);
 
-  long pw, ph, phr, pvr; // Printer width, height, horizontal and vertical resolution
-  xvt_app_escape (XVT_ESC_GET_PRINTER_INFO, printer().get_printrcd(), &ph, &pw, &pvr, &phr);
-	
-	TString test(fd._columns);
-	test.fill('M', fd._columns);
-	for (int size = fd._size; size > 0; size--)
-	{
-    const int w = xvt_dwin_get_text_width(win, (char*)(const char*)test, fd._columns);
-		if (w <= phr)
-		  break;
-	}
-    xvt_vobj_destroy(win);	
-	if (size > 0)
-	  fd._size = size;
-	
-  return FALSE;
+	    const int w = xvt_dwin_get_text_width(win, (char*)(const char*)test, fd._columns);
+			if (w <= ph)
+			  break;
+		}
+		
+		if (size > 0)
+		  fd._size = size;  
+		  
+		xvt_vobj_destroy(win);
+	}	
+  
+  return win != NULL_WIN;
 }
 
 int TPrinter::calc_font_size(int columns) const