diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c
index c97e8fd1717..84cad9366d5 100644
--- a/gdb/tui/tui-io.c
+++ b/gdb/tui/tui-io.c
@@ -319,7 +319,9 @@ tui_apply_style (WINDOW *w, ui_file_style style)
   wattron (w, A_NORMAL);
   wattroff (w, A_BOLD);
   wattroff (w, A_DIM);
+#ifdef  A_ITALIC
   wattroff (w, A_ITALIC);
+#endif
   wattroff (w, A_UNDERLINE);
   wattroff (w, A_REVERSE);
   if (last_color_pair != -1)
@@ -368,8 +370,10 @@ tui_apply_style (WINDOW *w, ui_file_style style)
       gdb_assert_not_reached ("invalid intensity");
     }
 
+#ifdef  A_ITALIC
   if (style.is_italic ())
     wattron (w, A_ITALIC);
+#endif
 
   if (style.is_underline ())
     wattron (w, A_UNDERLINE);
diff --git a/gdb/ui-style.c b/gdb/ui-style.c
index 9a58e4dd2ae..d450c3e6079 100644
--- a/gdb/ui-style.c
+++ b/gdb/ui-style.c
@@ -594,7 +594,11 @@ colorsupport ()
     {
       std::vector<color_space> result = {color_space::MONOCHROME};
 
-      int colors = tgetnum ("Co");
+      /* ncurses versions prior to 6.1 (and other curses
+	 implementations) declare the tgetnum argument to be
+	 'char *', so we need the const_cast, since C++ will not
+	 implicitly convert.  */
+      int colors = tgetnum (const_cast<char*> ("Co"));
       if (colors >= 8)
 	result.push_back (color_space::ANSI_8COLOR);
       if (colors >= 16)