diff --git a/.fmf/version b/.fmf/version
deleted file mode 100644
index d00491f..0000000
--- a/.fmf/version
+++ /dev/null
@@ -1 +0,0 @@
-1
diff --git a/.gitignore b/.gitignore
index e28cffa..e3fb872 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,2 @@
-/*.tar.xz
+/*.tar.gz
 /*.zip
diff --git a/plans/ci.fmf b/plans/ci.fmf
deleted file mode 100644
index d890aec..0000000
--- a/plans/ci.fmf
+++ /dev/null
@@ -1,6 +0,0 @@
-summary: Run CI tests
-discover:
-    how: fmf
-execute:
-    how: tmt
-
diff --git a/python-ruamel-yaml.spec b/python-ruamel-yaml.spec
index 93c571e..4d24128 100644
--- a/python-ruamel-yaml.spec
+++ b/python-ruamel-yaml.spec
@@ -1,8 +1,10 @@
 # Breaks the circular dependency with ruamel.yaml.clib.
 %bcond_with bootstrap
 
+%global commit 6f41eb6001661917fceb0e88ed0693ae1a7c50f4
+
 Name:           python-ruamel-yaml
-Version:        0.19.1
+Version:        0.18.6
 Release:        %autorelease
 Summary:        YAML 1.2 loader/dumper package for Python
 
@@ -10,7 +12,7 @@ Summary:        YAML 1.2 loader/dumper package for Python
 License:        MIT
 URL:            https://sourceforge.net/projects/ruamel-yaml
 # The PyPI sdist does not contain tests, so we use a snapshot from SourceForge
-Source:         https://yaml.dev/ruamel-dl-tagged-releases/ruamel.yaml-%{version}.tar.xz
+Source:         https://sourceforge.net/code-snapshots/hg/r/ru/ruamel-yaml/code/ruamel-yaml-code-%{commit}.zip
 
 BuildArch:      noarch
 
@@ -28,19 +30,20 @@ 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}
+%autosetup -n ruamel-yaml-code-%{commit}
+# 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 +65,5 @@ 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..f52e86d 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (ruamel.yaml-0.19.1.tar.xz) = bf9eb8e40f506d6f3f34aee5f5ec74eb93bfda2b27022f6ad62dfac724b9e0847d61e3159d284bada7dec147992aaf509804f7139818de5bc85aa328bc32601f
+SHA512 (ruamel-yaml-code-6f41eb6001661917fceb0e88ed0693ae1a7c50f4.zip) = 49fc9ef87e59b723803659300a8dc2c33d596bc2e1effa5235f26cf51fb08c0e6e0d2c386d54c290f97d63dc2a8956802a02c90e4a52881a2cd5d38daf1b0318
diff --git a/tests/main.fmf b/tests/main.fmf
deleted file mode 100644
index 1cfafe2..0000000
--- a/tests/main.fmf
+++ /dev/null
@@ -1 +0,0 @@
-component: python-ruamel-yaml
diff --git a/tests/sf534/main.fmf b/tests/sf534/main.fmf
deleted file mode 100644
index 5480ac5..0000000
--- a/tests/sf534/main.fmf
+++ /dev/null
@@ -1,5 +0,0 @@
-summary: Regression test for upstream ticket 534
-require: python3-ruamel-yaml
-link:
-  - verifies: https://sourceforge.net/p/ruamel-yaml/tickets/534/
-test: python3 test.py
diff --git a/tests/sf534/test.py b/tests/sf534/test.py
deleted file mode 100644
index 8302605..0000000
--- a/tests/sf534/test.py
+++ /dev/null
@@ -1,32 +0,0 @@
-# Taken from https://sourceforge.net/p/ruamel-yaml/tickets/534/
-
-from io import StringIO
-from ruamel.yaml import YAML
-
-original = '0: foo\n'
-py_original = {0: 'foo'}
-prefix = '%YAML 1.1\n---\n'
-
-yaml = YAML()
-yaml.version = (1, 1)
-
-loaded = yaml.load(original)
-assert loaded == py_original
-
-print('Fresh')
-stream = StringIO()
-yaml.dump(py_original, stream)
-fresh = stream.getvalue()
-print(fresh)
-assert fresh.startswith(prefix)
-trimmed = fresh[len(prefix):]
-assert trimmed == original, f"{trimmed!r} != {original!r}"
-
-print('Round trip')
-stream = StringIO()
-yaml.dump(loaded, stream)
-round_tripped = stream.getvalue()
-print(round_tripped)
-assert round_tripped.startswith(prefix)
-trimmed = round_tripped[len(prefix):]
-assert trimmed == original, f"{trimmed!r} != {original!r}"