diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7fcfebbeb7..93d20b54c4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-04-05  Pedro Alves  <palves@redhat.com>
+
+	* common/gdb_optional.h (optional::optional): Make constexpr and
+	initialize m_dummy.
+
 2017-04-04  John Baldwin  <jhb@FreeBSD.org>
 
 	* amd64-fbsd-tdep.c: Remove "bsd-uthread.h" include.
diff --git a/gdb/common/gdb_optional.h b/gdb/common/gdb_optional.h
index fef7a73e02..ad1119f2e8 100644
--- a/gdb/common/gdb_optional.h
+++ b/gdb/common/gdb_optional.h
@@ -34,8 +34,9 @@ class optional
 {
 public:
 
-  optional ()
-    : m_instantiated (false)
+  constexpr optional ()
+    : m_dummy (),
+      m_instantiated (false)
   {
   }