Index: include/experimental/optional
===================================================================
--- include/experimental/optional
+++ include/experimental/optional
@@ -562,7 +562,7 @@
 
     template <class _Up>
     _LIBCPP_INLINE_VISIBILITY
-    value_type value_or(_Up&& __v) &&
+    constexpr value_type value_or(_Up&& __v) &&
     {
         static_assert(is_move_constructible<value_type>::value,
                       "optional<T>::value_or: T must be move constructible");
Index: include/optional
===================================================================
--- include/optional
+++ include/optional
@@ -893,7 +893,7 @@
 
     template <class _Up>
     _LIBCPP_INLINE_VISIBILITY
-    value_type value_or(_Up&& __v) &&
+    constexpr value_type value_or(_Up&& __v) &&
     {
         static_assert(is_move_constructible_v<value_type>,
                       "optional<T>::value_or: T must be move constructible");
Index: test/std/experimental/optional/optional.object/optional.object.observe/value_or.pass.cpp
===================================================================
--- test/std/experimental/optional/optional.object/optional.object.observe/value_or.pass.cpp
+++ test/std/experimental/optional/optional.object/optional.object.observe/value_or.pass.cpp
@@ -10,7 +10,7 @@
 // UNSUPPORTED: c++98, c++03, c++11
 // <optional>
 
-// template <class U> T optional<T>::value_or(U&& v) &&;
+// template <class U> constexpr T optional<T>::value_or(U&& v) &&;
 
 #include <experimental/optional>
 #include <type_traits>
@@ -24,43 +24,49 @@
 {
     int i_;
 
-    Y(int i) : i_(i) {}
+    constexpr Y(int i) : i_(i) {}
 };
 
 struct X
 {
     int i_;
 
-    X(int i) : i_(i) {}
-    X(X&& x) : i_(x.i_) {x.i_ = 0;}
-    X(const Y& y) : i_(y.i_) {}
-    X(Y&& y) : i_(y.i_+1) {}
+    constexpr X(int i) : i_(i) {}
+    constexpr X(X&& x) : i_(x.i_) {x.i_ = 0;}
+    constexpr X(const Y& y) : i_(y.i_) {}
+    constexpr X(Y&& y) : i_(y.i_+1) {}
     friend constexpr bool operator==(const X& x, const X& y)
         {return x.i_ == y.i_;}
 };
 
-int main()
+constexpr int test()
 {
     {
         optional<X> opt(in_place, 2);
         Y y(3);
-        assert(std::move(opt).value_or(y) == 2);
-        assert(*opt == 0);
+        if (!(std::move(opt).value_or(y) == 2)) std::abort();
+        if (!(*opt == 0)) std::abort();
     }
     {
         optional<X> opt(in_place, 2);
-        assert(std::move(opt).value_or(Y(3)) == 2);
-        assert(*opt == 0);
+        if (!(std::move(opt).value_or(Y(3)) == 2)) std::abort();
+        if (!(*opt == 0)) std::abort();
     }
     {
         optional<X> opt;
         Y y(3);
-        assert(std::move(opt).value_or(y) == 3);
-        assert(!opt);
+        if (!(std::move(opt).value_or(y) == 3)) std::abort();
+        if (!(!opt)) std::abort();
     }
     {
         optional<X> opt;
-        assert(std::move(opt).value_or(Y(3)) == 4);
-        assert(!opt);
+        if (!(std::move(opt).value_or(Y(3)) == 4)) std::abort();
+        if (!(!opt)) std::abort();
     }
+    return 0;
+}
+
+int main()
+{
+    static_assert(test() == 0, "");
 }
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
===================================================================
--- test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
@@ -10,7 +10,7 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // <optional>
 
-// template <class U> T optional<T>::value_or(U&& v) &&;
+// template <class U> constexpr T optional<T>::value_or(U&& v) &&;
 
 #include <optional>
 #include <type_traits>
@@ -26,22 +26,22 @@
 {
     int i_;
 
-    Y(int i) : i_(i) {}
+    constexpr Y(int i) : i_(i) {}
 };
 
 struct X
 {
     int i_;
 
-    X(int i) : i_(i) {}
-    X(X&& x) : i_(x.i_) {x.i_ = 0;}
-    X(const Y& y) : i_(y.i_) {}
-    X(Y&& y) : i_(y.i_+1) {}
+    constexpr X(int i) : i_(i) {}
+    constexpr X(X&& x) : i_(x.i_) {x.i_ = 0;}
+    constexpr X(const Y& y) : i_(y.i_) {}
+    constexpr X(Y&& y) : i_(y.i_+1) {}
     friend constexpr bool operator==(const X& x, const X& y)
         {return x.i_ == y.i_;}
 };
 
-int main()
+constexpr int test()
 {
     {
         optional<X> opt(in_place, 2);
@@ -65,4 +65,10 @@
         assert(std::move(opt).value_or(Y(3)) == 4);
         assert(!opt);
     }
+    return 0;
+}
+
+int main()
+{
+    static_assert(test() == 0);
 }