diff --git a/libcxx/test/libcxx/clang_tidy.sh.cpp b/libcxx/test/libcxx/clang_tidy.sh.cpp
--- a/libcxx/test/libcxx/clang_tidy.sh.cpp
+++ b/libcxx/test/libcxx/clang_tidy.sh.cpp
@@ -27,6 +27,7 @@
 // and should not be edited manually.
 
 // Top level headers
+#include <__config>
 #include <algorithm>
 #include <any>
 #include <array>
@@ -204,6 +205,7 @@
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
diff --git a/libcxx/test/libcxx/double_include.sh.cpp b/libcxx/test/libcxx/double_include.sh.cpp
--- a/libcxx/test/libcxx/double_include.sh.cpp
+++ b/libcxx/test/libcxx/double_include.sh.cpp
@@ -28,6 +28,7 @@
 // and should not be edited manually.
 
 // Top level headers
+#include <__config>
 #include <algorithm>
 #include <any>
 #include <array>
@@ -205,6 +206,7 @@
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
diff --git a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/min_max_macros.compile.pass.cpp
@@ -28,6 +28,7 @@
 // and should not be edited manually.
 
 // Top level headers
+#include <__config>
 #include <algorithm>
 TEST_MACROS();
 #include <any>
@@ -321,6 +322,7 @@
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 #    include <experimental/algorithm>
 TEST_MACROS();
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
diff --git a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
--- a/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
+++ b/libcxx/test/libcxx/nasty_macros.compile.pass.cpp
@@ -138,6 +138,7 @@
 // and should not be edited manually.
 
 // Top level headers
+#include <__config>
 #include <algorithm>
 #include <any>
 #include <array>
@@ -315,6 +316,7 @@
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
diff --git a/libcxx/test/libcxx/no_assert_include.compile.pass.cpp b/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
--- a/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
+++ b/libcxx/test/libcxx/no_assert_include.compile.pass.cpp
@@ -24,6 +24,7 @@
 // and should not be edited manually.
 
 // Top level headers
+#include <__config>
 #include <algorithm>
 #include <any>
 #include <array>
@@ -200,6 +201,7 @@
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 #    include <experimental/algorithm>
 #    ifndef _LIBCPP_HAS_NO_EXPERIMENTAL_COROUTINES
 #        include <experimental/coroutine>
diff --git a/libcxx/utils/generate_header_tests.py b/libcxx/utils/generate_header_tests.py
--- a/libcxx/utils/generate_header_tests.py
+++ b/libcxx/utils/generate_header_tests.py
@@ -85,10 +85,12 @@
 
 headers_template = """\
 // Top level headers
+#include <__config>
 {top_level_headers}
 
 // experimental headers
 #if __cplusplus >= 201103L
+#    include <experimental/__config>
 {experimental_headers}
 #endif // __cplusplus >= 201103L