diff --git a/libcxx/include/__algorithm/pstl_find.h b/libcxx/include/__algorithm/pstl_find.h
--- a/libcxx/include/__algorithm/pstl_find.h
+++ b/libcxx/include/__algorithm/pstl_find.h
@@ -15,7 +15,6 @@
 #include <__algorithm/pstl_frontend_dispatch.h>
 #include <__config>
 #include <__iterator/cpp17_iterator_concepts.h>
-#include <__iterator/iterator_traits.h>
 #include <__type_traits/enable_if.h>
 #include <__type_traits/is_execution_policy.h>
 #include <__type_traits/remove_cvref.h>
diff --git a/libcxx/include/__pstl/internal/execution_impl.h b/libcxx/include/__pstl/internal/execution_impl.h
--- a/libcxx/include/__pstl/internal/execution_impl.h
+++ b/libcxx/include/__pstl/internal/execution_impl.h
@@ -14,11 +14,9 @@
 #include <__iterator/iterator_traits.h>
 #include <__type_traits/conditional.h>
 #include <__type_traits/conjunction.h>
-#include <__type_traits/decay.h>
-#include <__type_traits/integral_constant.h>
 #include <__type_traits/is_base_of.h>
 
-#include <__pstl/internal/execution_defs.h>
+#include "execution_defs.h"
 
 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
 
diff --git a/libcxx/include/__pstl/internal/parallel_backend_serial.h b/libcxx/include/__pstl/internal/parallel_backend_serial.h
--- a/libcxx/include/__pstl/internal/parallel_backend_serial.h
+++ b/libcxx/include/__pstl/internal/parallel_backend_serial.h
@@ -14,7 +14,6 @@
 #include <__memory/allocator.h>
 #include <__pstl/internal/execution_impl.h>
 #include <__utility/forward.h>
-#include <cstddef>
 
 #if !defined(_LIBCPP_HAS_NO_INCOMPLETE_PSTL) && _LIBCPP_STD_VER >= 17
 
diff --git a/libcxx/include/__pstl/internal/unseq_backend_simd.h b/libcxx/include/__pstl/internal/unseq_backend_simd.h
--- a/libcxx/include/__pstl/internal/unseq_backend_simd.h
+++ b/libcxx/include/__pstl/internal/unseq_backend_simd.h
@@ -12,15 +12,12 @@
 
 #include <__config>
 #include <__functional/operations.h>
-#include <__iterator/iterator_traits.h>
 #include <__type_traits/is_arithmetic.h>
-#include <__type_traits/is_same.h>
-#include <__utility/move.h>
 #include <__utility/pair.h>
 #include <cstddef>
 #include <cstdint>
 
-#include <__pstl/internal/utils.h>
+#include "utils.h"
 
 // This header defines the minimum set of vector routines required
 // to support parallel STL.