diff --git a/python-ruamel-yaml.spec b/python-ruamel-yaml.spec
index 93c571e..10cd123 100644
--- a/python-ruamel-yaml.spec
+++ b/python-ruamel-yaml.spec
@@ -2,7 +2,7 @@
 %bcond_with bootstrap
 
 Name:           python-ruamel-yaml
-Version:        0.19.1
+Version:        0.18.16
 Release:        %autorelease
 Summary:        YAML 1.2 loader/dumper package for Python
 
@@ -28,19 +28,20 @@ BuildRequires:  python3-pytest
 
 %py_provides python3-ruamel.yaml
 
-%if !%{with bootstrap}
-# ruamel.yaml.clibz is not available in Fedora (and probably never will
-# be), so require the old clib backend
-Requires:       python3-ruamel-yaml+oldlibyaml = %{version}-%{release}
-%endif
-
 %description -n python3-ruamel-yaml %{_description}
 
 %prep
 %autosetup -n ruamel.yaml-%{version}
+# Upstream upper-bounds the Python interpeter versions with which the C
+# implementation (ruamel.yaml.clib dependency) may be used. Patch this out.
+sed -r -i 's/( and python_version<"[^"]+")(.*ruamel\.yaml\.clib)/\2/' \
+    __init__.py
+%if %{with bootstrap}
+sed -r -i 's/^([[:blank:]]*)(.*ruamel\.yaml\.clib)/\1# \2/' __init__.py
+%endif
 
 %generate_buildrequires
-%pyproject_buildrequires %{!?with_bootstrap:-x oldlibyaml}
+%pyproject_buildrequires
 
 %build
 %pyproject_wheel
@@ -62,7 +63,5 @@ k="${k-}${k+ and }not test_dump_cyaml_1_2"
 %files -n python3-ruamel-yaml -f %{pyproject_files}
 %doc README.md
 
-%pyproject_extras_subpkg -n python3-ruamel-yaml oldlibyaml
-
 %changelog
 %autochangelog
diff --git a/sources b/sources
index f0e723c..b90ca66 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (ruamel.yaml-0.19.1.tar.xz) = bf9eb8e40f506d6f3f34aee5f5ec74eb93bfda2b27022f6ad62dfac724b9e0847d61e3159d284bada7dec147992aaf509804f7139818de5bc85aa328bc32601f
+SHA512 (ruamel.yaml-0.18.16.tar.xz) = 1d4c28c6769167d044cfc506035a0d7e13b533ecbfa2287b00035e9036c400c9cbd86fa96921a7e6a9c9b286f9bf4970637a09d4747c5bf7315b37db353720f6