diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -5785,4 +5785,14 @@
 
 _LIBCPP_POP_MACROS
 
+// If <execution> has already been included, pull in implementations,
+// otherwise just pull in forward declarations.
+#include <pstl/internal/pstl_config.h>
+#if defined(__PSTL_EXECUTION_POLICIES_DEFINED)
+#    include <pstl/internal/glue_algorithm_impl.h>
+#else
+#    include <pstl/internal/glue_algorithm_defs.h>
+#    define __PSTL_ALGORITHM_FORWARD_DECLARED 1
+#endif
+
 #endif  // _LIBCPP_ALGORITHM
diff --git a/libcxx/include/execution b/libcxx/include/execution
new file mode 100644
--- /dev/null
+++ b/libcxx/include/execution
@@ -0,0 +1,32 @@
+// -*- C++ -*-
+//===------------------------- execution ---------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXECUTION
+#define _LIBCPP_EXECUTION
+
+#include <pstl/internal/pstl_config.h>
+#include <pstl/internal/execution_defs.h>
+
+#define __PSTL_EXECUTION_POLICIES_DEFINED 1
+
+#if defined(__PSTL_ALGORITHM_FORWARD_DECLARED)
+#    include <pstl/internal/glue_algorithm_impl.h>
+#endif
+
+#if defined(__PSTL_MEMORY_FORWARD_DECLARED)
+#    include <pstl/internal/glue_memory_impl.h>
+#endif
+
+#if defined(__PSTL_NUMERIC_FORWARD_DECLARED)
+#    include <pstl/internal/glue_numeric_impl.h>
+#endif
+
+#include <pstl/internal/glue_execution_defs.h>
+
+#endif /* _LIBCPP_EXECUTION */
diff --git a/libcxx/include/memory b/libcxx/include/memory
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -5672,4 +5672,14 @@
 
 _LIBCPP_POP_MACROS
 
+// If <execution> has already been included, pull in implementations,
+// otherwise just pull in forward declarations.
+#include <pstl/internal/pstl_config.h>
+#if defined(__PSTL_EXECUTION_POLICIES_DEFINED)
+#    include <pstl/internal/glue_memory_impl.h>
+#else
+#    include <pstl/internal/glue_memory_defs.h>
+#    define __PSTL_MEMORY_FORWARD_DECLARED 1
+#endif
+
 #endif  // _LIBCPP_MEMORY
diff --git a/libcxx/include/numeric b/libcxx/include/numeric
--- a/libcxx/include/numeric
+++ b/libcxx/include/numeric
@@ -558,4 +558,14 @@
 
 _LIBCPP_POP_MACROS
 
+// If <execution> has already been included, pull in implementations,
+// otherwise just pull in forward declarations.
+#include <pstl/internal/pstl_config.h>
+#if defined(__PSTL_EXECUTION_POLICIES_DEFINED)
+#    include <pstl/internal/glue_numeric_impl.h>
+#else
+#    include <pstl/internal/glue_numeric_defs.h>
+#    define __PSTL_NUMERIC_FORWARD_DECLARED 1
+#endif
+
 #endif  // _LIBCPP_NUMERIC
diff --git a/libcxx/lib/CMakeLists.txt b/libcxx/lib/CMakeLists.txt
--- a/libcxx/lib/CMakeLists.txt
+++ b/libcxx/lib/CMakeLists.txt
@@ -122,6 +122,11 @@
   add_library_flags(iso_stdio_wide_specifiers)
 endif()
 
+find_package(ParallelSTL)
+if (NOT TARGET pstl::ParallelSTL)
+  message(FATAL_ERROR "Could not find ParallelSTL")
+endif()
+
 function(cxx_set_common_defines name)
   if(LIBCXX_CXX_ABI_HEADER_TARGET)
     add_dependencies(${name} ${LIBCXX_CXX_ABI_HEADER_TARGET})
@@ -148,6 +153,10 @@
                                  # in printf, scanf.
                                  _CRT_STDIO_ISO_WIDE_SPECIFIERS)
   endif()
+
+  if (TARGET pstl::ParallelSTL)
+    target_link_libraries(${name} PUBLIC pstl::ParallelSTL)
+  endif()
 endfunction()
 
 split_list(LIBCXX_COMPILE_FLAGS)