diff --git a/libcxx/include/__pstl/internal/pstl_config.h b/libcxx/include/__pstl/internal/pstl_config.h
--- a/libcxx/include/__pstl/internal/pstl_config.h
+++ b/libcxx/include/__pstl/internal/pstl_config.h
@@ -25,29 +25,14 @@
 
 // Enable SIMD for compilers that support OpenMP 4.0
 #if (defined(_OPENMP) && _OPENMP >= 201307)
-#    define _PSTL_PRAGMA_SIMD _PSTL_PRAGMA(omp simd)
-#    define _PSTL_PRAGMA_DECLARE_SIMD _PSTL_PRAGMA(omp declare simd)
-#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _PSTL_PRAGMA(omp simd reduction(PRM))
-#else //no simd
-#    define _PSTL_PRAGMA_SIMD
-#    define _PSTL_PRAGMA_DECLARE_SIMD
-#    define _PSTL_PRAGMA_SIMD_REDUCTION(PRM)
-#endif //Enable SIMD
-
-// TODO: find out when to enable these annotations
-#if 0
-#    define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
-#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
-#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
-#else
-#    define _PSTL_PRAGMA_SIMD_SCAN(PRM)
-#    define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
-#    define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
-#endif
-
-#if defined(_OPENMP) && _OPENMP >= 201307
-#    define _PSTL_UDR_PRESENT
-#endif
+
+#  define _PSTL_UDR_PRESENT
+#  define _PSTL_PRAGMA_SIMD _PSTL_PRAGMA(omp simd)
+#  define _PSTL_PRAGMA_DECLARE_SIMD _PSTL_PRAGMA(omp declare simd)
+#  define _PSTL_PRAGMA_SIMD_REDUCTION(PRM) _PSTL_PRAGMA(omp simd reduction(PRM))
+#  define _PSTL_PRAGMA_SIMD_SCAN(PRM) _PSTL_PRAGMA(omp simd reduction(inscan, PRM))
+#  define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan inclusive(PRM))
+#  define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM) _PSTL_PRAGMA(omp scan exclusive(PRM))
 
 // Declaration of reduction functor, where
 // NAME - the name of the functor
@@ -56,7 +41,19 @@
 // omp_out - refers to the final value of the combiner operator
 // omp_priv - refers to the private copy of the initial value
 // omp_orig - refers to the original variable to be reduced
-#define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)                                                                       \
+#  define _PSTL_PRAGMA_DECLARE_REDUCTION(NAME, OP)                                                                     \
     _PSTL_PRAGMA(omp declare reduction(NAME:OP : omp_out(omp_in)) initializer(omp_priv = omp_orig))
 
+#else // (defined(_OPENMP) && _OPENMP >= 201307)
+
+#  define _PSTL_PRAGMA_SIMD
+#  define _PSTL_PRAGMA_DECLARE_SIMD
+#  define _PSTL_PRAGMA_SIMD_REDUCTION(PRM)
+#  define _PSTL_PRAGMA_SIMD_SCAN(PRM)
+#  define _PSTL_PRAGMA_SIMD_INCLUSIVE_SCAN(PRM)
+#  define _PSTL_PRAGMA_SIMD_EXCLUSIVE_SCAN(PRM)
+#  define _PSTL_PRAGMA_DECLARE_REDUCTION(RPM)
+
+#endif // (defined(_OPENMP) && _OPENMP >= 201307)
+
 #endif /* _PSTL_CONFIG_H */