diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8fe152fe..e574b3cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 * ✨ Add `--enable-tables` to the CLI for file, standard input and interactive parsing in [#422](https://github.com/executablebooks/markdown-it-py/pull/422)
 * 🐛 Fix CLI interactive mode joining input lines with an extra newline, which split every line into its own paragraph and broke hard line breaks, in [#172](https://github.com/executablebooks/markdown-it-py/issues/172)
 * 📚 Document the Python renderer constructor contract.
+* 🔧 Drop the optional dependency on the `commonmark` package and its benchmark, since the upstream package is unmaintained, in [#401](https://github.com/executablebooks/markdown-it-py/pull/401)
 
 ## 4.2.0 - 2026-05-07
 
diff --git a/benchmarking/bench_packages.py b/benchmarking/bench_packages.py
index 084557a9..ea668a6e 100644
--- a/benchmarking/bench_packages.py
+++ b/benchmarking/bench_packages.py
@@ -35,14 +35,6 @@ def test_mistune(benchmark, spec_text):
     benchmark(mistune.markdown, spec_text)
 
 
-@pytest.mark.benchmark(group="packages")
-def test_commonmark_py(benchmark, spec_text):
-    import commonmark
-
-    benchmark.extra_info["version"] = "0.9.1"
-    benchmark(commonmark.commonmark, spec_text)
-
-
 @pytest.mark.benchmark(group="packages")
 def test_pymarkdown(benchmark, spec_text):
     import markdown
diff --git a/docs/performance.md b/docs/performance.md
index f0291f4a..51747a8b 100644
--- a/docs/performance.md
+++ b/docs/performance.md
@@ -15,7 +15,7 @@ tox -e py311-bench-packages -- --benchmark-columns mean,stddev
 | mistune[^2]          | 3.0.1   | 80.409    | 2.335   |
 | **markdown-it-py**   | 3.0.0   | 97.242    | 4.427   |
 | mistletoe            | 1.1.0   | 99.633    | 4.628   |
-| commonmark-py        | 0.9.1   | 300.403   | 9.706   |
+| commonmark-py[^3]    | 0.9.1   | 300.403   | 9.706   |
 | pymarkdown           | 3.4.3   | 387.775   | 10.394  |
 | pymarkdown (+extras) | 3.4.3   | 646.564   | 11.316  |
 | panflute             | 2.3.0   | 860.105   | 208.607 |
@@ -26,3 +26,4 @@ As you can see, `markdown-it-py` doesn't pay with speed for its flexibility.
 [^2]: `mistune` is not CommonMark compliant, which is what allows for its
 faster parsing, at the expense of issues, for example, with nested inline parsing.
 See [mistletoe's explanation](https://github.com/miyuchina/mistletoe/blob/master/performance.md) for further details.
+[^3]: `commonmark-py` is deprecated and no longer maintained (its last release was in 2019), so it has been removed from the benchmark suite; the figures shown are from the last run that included it.
diff --git a/pyproject.toml b/pyproject.toml
index df44491f..de6a855f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,6 @@ Documentation = "https://markdown-it-py.readthedocs.io"
 
 [project.optional-dependencies]
 compare = [
-    "commonmark~=0.9",
     "markdown~=3.4",
     "mistletoe~=1.0",
     "mistune~=3.0",