diff --git a/libcxx/docs/ReleaseNotes.rst b/libcxx/docs/ReleaseNotes.rst
--- a/libcxx/docs/ReleaseNotes.rst
+++ b/libcxx/docs/ReleaseNotes.rst
@@ -66,6 +66,9 @@
   - C++2b: ``atomic``, ``bit``, ``cstdint``, ``cstdlib``, ``cstring``, ``initializer_list``, ``limits``, ``new``,
            ``stdexcept``, ``system_error``, ``type_traits``, ``typeinfo``
 
+- ``<algorithm>`` no longer includes ``<chrono>`` in any C++ version (it was prevously included in C++17 and earlier).
+  This was necessary to break include cycles, which are not allowed with clang modules.
+
 - The headers ``<experimental/algorithm>`` and ``<experimental/functional>`` have been removed, since all the contents
   have been implemented in namespace ``std`` for at least two releases.
 
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -1921,10 +1921,6 @@
 #  include <__pstl_algorithm>
 #endif
 
-#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
-#  include <chrono>
-#endif
-
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <atomic>
 #  include <bit>
diff --git a/libcxx/test/libcxx/transitive_includes/cxx03.csv b/libcxx/test/libcxx/transitive_includes/cxx03.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx03.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx03.csv
@@ -1,6 +1,5 @@
 algorithm atomic
 algorithm bit
-algorithm chrono
 algorithm climits
 algorithm concepts
 algorithm cstddef
diff --git a/libcxx/test/libcxx/transitive_includes/cxx11.csv b/libcxx/test/libcxx/transitive_includes/cxx11.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx11.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx11.csv
@@ -1,6 +1,5 @@
 algorithm atomic
 algorithm bit
-algorithm chrono
 algorithm climits
 algorithm concepts
 algorithm cstddef
diff --git a/libcxx/test/libcxx/transitive_includes/cxx14.csv b/libcxx/test/libcxx/transitive_includes/cxx14.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx14.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx14.csv
@@ -1,6 +1,5 @@
 algorithm atomic
 algorithm bit
-algorithm chrono
 algorithm climits
 algorithm concepts
 algorithm cstddef
diff --git a/libcxx/test/libcxx/transitive_includes/cxx17.csv b/libcxx/test/libcxx/transitive_includes/cxx17.csv
--- a/libcxx/test/libcxx/transitive_includes/cxx17.csv
+++ b/libcxx/test/libcxx/transitive_includes/cxx17.csv
@@ -1,6 +1,5 @@
 algorithm atomic
 algorithm bit
-algorithm chrono
 algorithm climits
 algorithm concepts
 algorithm cstddef