diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 71aea523fe..8c07086ac2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-05-13  Eli Zaretskii  <eliz@gnu.org>
+
+	* tui/tui.c (tui_enable): Cast "unknown" to 'char *' to avoid a
+	C++ compiler warning.
+
 2017-05-12  Tom Tromey  <tom@tromey.com>
 
 	PR rust/21483:
diff --git a/gdb/tui/tui.c b/gdb/tui/tui.c
index eb489b1533..c918f3e236 100644
--- a/gdb/tui/tui.c
+++ b/gdb/tui/tui.c
@@ -427,7 +427,7 @@ tui_enable (void)
       /* The MinGW port of ncurses requires $TERM to be unset in order
 	 to activate the Windows console driver.  */
       if (s == NULL)
-	s = newterm ("unknown", stdout, stdin);
+	s = newterm ((char *) "unknown", stdout, stdin);
 #endif
       if (s == NULL)
 	{