diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index aab9f7d..74fc4e6 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -33,7 +33,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ['pypy-3.10', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['pypy-3.10', '3.10', '3.11', '3.12', '3.13', '3.14']
 
     steps:
     - uses: actions/checkout@v4
@@ -59,6 +59,28 @@ jobs:
         # coverage is informational: an upload failure must not fail CI
         fail_ci_if_error: false
 
+  tests-floor:
+
+    # the oldest markdown-it-py the package declares (`markdown-it-py>=3.0.0`):
+    # the plugins that need 4.1 skip their tests and check their version guard
+    name: tests (3.10, markdown-it-py 3.0.0)
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.10
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.10"
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e .[testing] markdown-it-py==3.0.0
+    - name: Check the installed markdown-it-py
+      run: python -c "import markdown_it; assert markdown_it.__version__ == '3.0.0', markdown_it.__version__"
+    - name: Run pytest
+      run: pytest
+
   build:
 
     name: Build distributions
@@ -103,6 +125,7 @@ jobs:
     needs:
     - pre-commit
     - tests
+    - tests-floor
     - build
     steps:
     - run: echo "Great success!"
@@ -110,7 +133,7 @@ jobs:
   publish:
 
     name: Publish to PyPI
-    needs: [pre-commit, tests, build]
+    needs: [pre-commit, tests, tests-floor, build]
     if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-latest
     permissions:
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1b32767..65ddc6d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -30,5 +30,5 @@ repos:
     rev: v2.4.1
     hooks:
     - id: mypy
-      additional_dependencies: [markdown-it-py~=3.0]
+      additional_dependencies: [markdown-it-py~=4.2]
       exclude: ^tests/
diff --git a/pyproject.toml b/pyproject.toml
index f6746e4..639ec91 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,11 +14,11 @@ classifiers = [
     "Intended Audience :: Developers",
     "License :: OSI Approved :: MIT License",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
-    "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Software Development :: Libraries :: Python Modules",
@@ -26,7 +26,7 @@ classifiers = [
 ]
 keywords = ["markdown", "markdown-it", "lexer", "parser", "development"]
 requires-python = ">=3.10"
-dependencies = ["markdown-it-py>=2.0.0,<5.0.0"]
+dependencies = ["markdown-it-py>=3.0.0,<5.0.0"]
 
 [project.urls]
 Homepage = "https://github.com/executablebooks/mdit-py-plugins"
diff --git a/tests/test_gfm.py b/tests/test_gfm.py
index 3bc3678..1b94dea 100644
--- a/tests/test_gfm.py
+++ b/tests/test_gfm.py
@@ -8,6 +8,10 @@
 
 from mdit_py_plugins.gfm import gfm_plugin
 
+# The plugin needs markdown-it-py >= 4.1.0 (it raises RuntimeError below that);
+# the guard itself is tested in test_mdit_version_guard.py, on every version.
+pytest.importorskip("markdown_it", minversion="4.1.0")
+
 FIXTURE_PATH = Path(__file__).parent.joinpath("fixtures", "gfm.md")
 
 
diff --git a/tests/test_gfm_autolink.py b/tests/test_gfm_autolink.py
index 16d0074..a7f236f 100644
--- a/tests/test_gfm_autolink.py
+++ b/tests/test_gfm_autolink.py
@@ -8,6 +8,10 @@
 
 from mdit_py_plugins.gfm_autolink import gfm_autolink_plugin
 
+# The plugin needs markdown-it-py >= 4.1.0 (it raises RuntimeError below that);
+# the guard itself is tested in test_mdit_version_guard.py, on every version.
+pytest.importorskip("markdown_it", minversion="4.1.0")
+
 FIXTURE_PATH = Path(__file__).parent.joinpath("fixtures", "gfm_autolink.md")
 
 
diff --git a/tests/test_mdit_version_guard.py b/tests/test_mdit_version_guard.py
new file mode 100644
index 0000000..363692c
--- /dev/null
+++ b/tests/test_mdit_version_guard.py
@@ -0,0 +1,38 @@
+"""The plugins that need markdown-it-py >= 4.1.0 refuse older versions.
+
+``test_gfm``, ``test_gfm_autolink`` and ``test_section_ref`` skip below 4.1.0,
+so their version guards are tested here, where they run on every supported version
+(CI runs the suite on the declared floor, markdown-it-py 3.0.0, as well as the latest).
+"""
+
+from types import SimpleNamespace
+
+from markdown_it import MarkdownIt
+from markdown_it import __version__ as mdit_version
+from packaging.version import Version
+import pytest
+
+from mdit_py_plugins.gfm import gfm_plugin
+from mdit_py_plugins.gfm_autolink import gfm_autolink_plugin
+from mdit_py_plugins.section_ref import section_ref_plugin
+
+
+@pytest.mark.skipif(
+    Version(mdit_version) >= Version("4.1.0"),
+    reason="needs markdown-it-py < 4.1.0 installed",
+)
+@pytest.mark.parametrize(
+    "plugin", [gfm_plugin, gfm_autolink_plugin, section_ref_plugin]
+)
+def test_raises_below_4_1(plugin):
+    """On markdown-it-py < 4.1.0 the plugin raises a clear error, not a late failure."""
+    with pytest.raises(RuntimeError, match=r"requires markdown-it-py >= 4\.1\.0"):
+        MarkdownIt().use(plugin)
+
+
+def test_section_ref_runtime_error():
+    """The plugin requires the ``add_terminator_char`` API (markdown-it-py >= 4.1.0)."""
+    md = MarkdownIt()
+    md.inline = SimpleNamespace()  # type: ignore[assignment]  # lacks add_terminator_char
+    with pytest.raises(RuntimeError, match="requires markdown-it-py"):
+        section_ref_plugin(md)
diff --git a/tests/test_section_ref.py b/tests/test_section_ref.py
index df777dc..fb1ee5f 100644
--- a/tests/test_section_ref.py
+++ b/tests/test_section_ref.py
@@ -1,6 +1,5 @@
 from pathlib import Path
 import time
-from types import SimpleNamespace
 
 from markdown_it import MarkdownIt
 from markdown_it.token import Token
@@ -9,6 +8,10 @@
 
 from mdit_py_plugins.section_ref import section_ref_plugin
 
+# The plugin needs markdown-it-py >= 4.1.0 (it raises RuntimeError below that);
+# the guard itself is tested in test_mdit_version_guard.py, on every version.
+pytest.importorskip("markdown_it", minversion="4.1.0")
+
 FIXTURE_PATH = Path(__file__).parent.joinpath("fixtures", "section_ref.md")
 
 
@@ -133,14 +136,6 @@ def test_token_shape_is_public_api():
     assert token.meta == {"numbers": [1, 2]}
 
 
-def test_runtime_error():
-    """The plugin requires the ``add_terminator_char`` API (markdown-it-py >= 4.1.0)."""
-    md = MarkdownIt()
-    md.inline = SimpleNamespace()  # type: ignore[assignment]  # lacks add_terminator_char
-    with pytest.raises(RuntimeError, match="requires markdown-it-py"):
-        section_ref_plugin(md)
-
-
 @pytest.mark.parametrize("line,title,input,expected", read_fixture_file(FIXTURE_PATH))
 def test_all(line, title, input, expected):
     md = MarkdownIt("commonmark").use(section_ref_plugin)
diff --git a/tox.ini b/tox.ini
index c14ddf5..89db037 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,7 +9,7 @@ envlist = py310
 [testenv]
 usedevelop = true
 
-[testenv:py{310,311,312,313}]
+[testenv:py{310,311,312,313,314}]
 extras = testing
 deps = markdown-it-py>=4.1.0
 commands = pytest {posargs}