diff --git a/include/algorithm b/include/algorithm
index 68e989a..d924a7d 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -2508,11 +2508,16 @@
     _Engine_result_type __mask0_;
     _Engine_result_type __mask1_;
 
+#ifdef _LIBCPP_HAS_NO_CONSTEXPR
     static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
-                                                         + _Working_result_type(1);
-    static const size_t __m = __log2<_Working_result_type, _Rp>::value;
-    static const size_t _WDt = numeric_limits<_Working_result_type>::digits;
-    static const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
+                                          + _Working_result_type(1);
+#else
+    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
+                                                      + _Working_result_type(1);
+#endif
+    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
+    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
+    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
 
 public:
     // constructors and seeding functions