diff --git a/src/pytest_doctest_docutils.py b/src/pytest_doctest_docutils.py
index 8ca4292..38a8184 100644
--- a/src/pytest_doctest_docutils.py
+++ b/src/pytest_doctest_docutils.py
@@ -23,7 +23,6 @@
 
 import _pytest
 from _pytest import outcomes
-from _pytest.doctest import DoctestItem
 from _pytest.outcomes import OutcomeException
 
 from doctest_docutils import DocutilsDocTestFinder, setup
@@ -31,12 +30,23 @@
 if TYPE_CHECKING:
     from doctest import _Out
 
+    from _pytest.doctest import DoctestItem
+
 logger = logging.getLogger(__name__)
 
 # Lazy definition of runner class
 RUNNER_CLASS = None
 
 
+def pytest_configure(config: pytest.Config) -> None:
+    """Disable pytest.doctest to prevent running tests twice.
+
+    Todo: Find a way to make these plugins cooperate without collecting twice.
+    """
+    if config.pluginmanager.has_plugin("doctest"):
+        config.pluginmanager.set_blocked("doctest")
+
+
 def pytest_unconfigure() -> None:
     global RUNNER_CLASS
 
@@ -170,7 +180,7 @@ def _DocTestRunner__patched_linecache_getlines(
 
 
 class DocTestDocutilsFile(pytest.Module):
-    def collect(self) -> Iterable[DoctestItem]:
+    def collect(self) -> Iterable["DoctestItem"]:
         setup()
 
         encoding = self.config.getini("doctest_encoding")
@@ -189,6 +199,7 @@ def collect(self) -> Iterable[DoctestItem]:
                 self.config
             ),
         )
+        from _pytest.doctest import DoctestItem
 
         for test in finder.find(
             text,
diff --git a/tests/test_pytest_doctest_docutils.py b/tests/test_pytest_doctest_docutils.py
new file mode 100644
index 0000000..c517f62
--- /dev/null
+++ b/tests/test_pytest_doctest_docutils.py
@@ -0,0 +1,178 @@
+import pathlib
+import textwrap
+import typing as t
+
+import pytest
+
+import _pytest.pytester
+
+FixtureFileDict = t.Dict[str, str]
+
+
+class PytestDocTestFinderFixture(t.NamedTuple):
+    # pytest
+    test_id: str
+
+    # Content
+    files: FixtureFileDict
+    tests_found: int
+
+
+FIXTURES = [
+    #
+    # Docutils
+    #
+    PytestDocTestFinderFixture(
+        test_id="reST-doctest_block",
+        files={
+            "example.rst": textwrap.dedent(
+                """
+>>> 4 + 4
+8
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="reST-doctest_directive",
+        files={
+            "example.rst": textwrap.dedent(
+                """
+.. doctest::
+
+   >>> 4 + 4
+   8
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    #
+    # Markdown / myst-parser
+    #
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_block",
+        files={
+            "example.md": textwrap.dedent(
+                """
+```
+>>> 4 + 4
+8
+```
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_block-indented",
+        files={
+            "example.md": textwrap.dedent(
+                """
+Here's a test:
+
+    >>> 4 + 4
+    8
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_directive-colons",
+        files={
+            "example.md": textwrap.dedent(
+                """
+:::{doctest}
+
+    >>> 4 + 4
+    8
+:::
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_directive-backticks",
+        files={
+            "example.md": textwrap.dedent(
+                """
+```{doctest}
+
+    >>> 4 + 4
+    8
+```
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_directive-eval-rst-colons",
+        files={
+            "example.md": textwrap.dedent(
+                """
+:::{eval-rst}
+
+   .. doctest::
+
+      >>> 4 + 4
+      8
+:::
+        """
+            )
+        },
+        tests_found=1,
+    ),
+    PytestDocTestFinderFixture(
+        test_id="MyST-doctest_directive-eval-rst-backticks",
+        files={
+            "example.md": textwrap.dedent(
+                """
+```{eval-rst}
+
+   .. doctest::
+
+      >>> 4 + 4
+      8
+```
+        """
+            )
+        },
+        tests_found=1,
+    ),
+]
+
+
+@pytest.mark.parametrize(
+    PytestDocTestFinderFixture._fields, FIXTURES, ids=[f.test_id for f in FIXTURES]
+)
+def test_pluginDocutilsDocTestFinder(
+    pytester: _pytest.pytester.Pytester,
+    tmp_path: pathlib.Path,
+    monkeypatch: pytest.MonkeyPatch,
+    test_id: str,
+    files: FixtureFileDict,
+    tests_found: int,
+) -> None:
+    # Initialize variables
+    pytester.plugins = ["pytest_doctest_docutils"]
+    pytester.makefile(".ini", pytest="[pytest]\naddopts=-p no:doctest -vv\n")
+    tests_path = tmp_path / "tests"
+    first_test_key = list(files.keys())[0]
+    first_test_filename = str(tests_path / first_test_key)
+
+    # Setup: Files
+    tests_path.mkdir()
+    for file_name, text in files.items():
+        rst_file = tests_path / file_name
+        rst_file.write_text(
+            text,
+            encoding="utf-8",
+        )
+
+    # Test
+    result = pytester.runpytest(str(first_test_filename))
+    result.assert_outcomes(passed=tests_found)