diff --git a/lib/spack/spack/build_systems/_package_api_v1.py b/lib/spack/spack/build_systems/_package_api_v1.py
new file mode 100644
index 00000000000..8a5f7853135
--- /dev/null
+++ b/lib/spack/spack/build_systems/_package_api_v1.py
@@ -0,0 +1,99 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+"""This module re-exports symbols that are part of the v1.0 Package API, but were removed in the
+v2.0 Package API after build systems were moved into the ``spack_repo.builtin`` package.
+In older versions of Spack, these symbols were re-exported from ``spack.package``."""
+
+from .aspell_dict import AspellDictPackage
+from .autotools import AutotoolsPackage
+from .bundle import BundlePackage
+from .cached_cmake import (
+    CachedCMakePackage,
+    cmake_cache_filepath,
+    cmake_cache_option,
+    cmake_cache_path,
+    cmake_cache_string,
+)
+from .cargo import CargoPackage
+from .cmake import CMakePackage, generator
+from .compiler import CompilerPackage
+from .cuda import CudaPackage
+from .generic import Package
+from .gnu import GNUMirrorPackage
+from .go import GoPackage
+from .intel import IntelPackage
+from .lua import LuaPackage
+from .makefile import MakefilePackage
+from .maven import MavenPackage
+from .meson import MesonPackage
+from .msbuild import MSBuildPackage
+from .nmake import NMakePackage
+from .octave import OctavePackage
+from .oneapi import (
+    INTEL_MATH_LIBRARIES,
+    IntelOneApiLibraryPackage,
+    IntelOneApiLibraryPackageWithSdk,
+    IntelOneApiPackage,
+    IntelOneApiStaticLibraryList,
+)
+from .perl import PerlPackage
+from .python import PythonExtension, PythonPackage
+from .qmake import QMakePackage
+from .r import RPackage
+from .racket import RacketPackage
+from .rocm import ROCmPackage
+from .ruby import RubyPackage
+from .scons import SConsPackage
+from .sip import SIPPackage
+from .sourceforge import SourceforgePackage
+from .sourceware import SourcewarePackage
+from .waf import WafPackage
+from .xorg import XorgPackage
+
+__all__ = [
+    "AspellDictPackage",
+    "AutotoolsPackage",
+    "BundlePackage",
+    "CachedCMakePackage",
+    "cmake_cache_filepath",
+    "cmake_cache_option",
+    "cmake_cache_path",
+    "cmake_cache_string",
+    "CargoPackage",
+    "CMakePackage",
+    "generator",
+    "CompilerPackage",
+    "CudaPackage",
+    "Package",
+    "GNUMirrorPackage",
+    "GoPackage",
+    "IntelPackage",
+    "IntelOneApiLibraryPackageWithSdk",
+    "IntelOneApiLibraryPackage",
+    "IntelOneApiStaticLibraryList",
+    "IntelOneApiPackage",
+    "INTEL_MATH_LIBRARIES",
+    "LuaPackage",
+    "MakefilePackage",
+    "MavenPackage",
+    "MesonPackage",
+    "MSBuildPackage",
+    "NMakePackage",
+    "OctavePackage",
+    "PerlPackage",
+    "PythonExtension",
+    "PythonPackage",
+    "QMakePackage",
+    "RacketPackage",
+    "RPackage",
+    "ROCmPackage",
+    "RubyPackage",
+    "SConsPackage",
+    "SIPPackage",
+    "SourceforgePackage",
+    "SourcewarePackage",
+    "WafPackage",
+    "XorgPackage",
+]