diff --git a/.gitignore b/.gitignore
index 0e1240c..b18bd4f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -73,4 +73,4 @@ docs/_build/
 .python-version
 
 # pytest-readme
-test_readme.py
+tests/test_readme.py
diff --git a/pyproject.toml b/pyproject.toml
index 5beefdd..0705fee 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,4 +16,4 @@ dynamic = ["version"]
 features = ["pyo3/extension-module"]
 
 [project.optional-dependencies]
-test = ["pytest", "pytest-readme"]
+test = ["pytest"]
diff --git a/tests/conftest.py b/tests/conftest.py
index 9ddc47b..01ca78f 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,3 +1,53 @@
-from pytest_readme import setup
+def parse_from_readme():
+    """
+    Adapted from https://github.com/boxed/pytest-readme
 
-setup()
+    Copyright (c) 2020, Anders Hovmöller
+
+    Under the BSD 3-Clause "New" or "Revised" License.
+    """
+    with open(
+        "tests/test_readme.py",
+        "w",
+        encoding="utf8",
+    ) as out, open("README.md", encoding="utf8") as readme:
+        output, mode = [], None
+
+        for i, line in enumerate(readme.readlines()):
+            output.append("\n")
+
+            if mode is None and line.strip() == "```python":
+                mode = "first_line"
+                output[i] = "def test_line_%s():\n" % i
+                continue
+
+            if line.strip() == "```":
+                if mode == "doctest":
+                    output[i] = '    """\n'
+                mode = None
+                continue
+
+            if mode == "first_line":
+                if line.strip() == "":
+                    mode = None
+                    output[i - 1] = "\n"
+                    continue
+
+                if line.strip().startswith(">>>"):
+                    mode = "doctest"
+                    output[i - 2] = (
+                        output[i - 1][:-1] + "  " + output[i - 2]
+                    )  # move the def line one line up
+                    output[i - 1] = '    """\n'
+                else:
+                    mode = "test"
+
+            if mode in ("doctest", "test"):
+                output[i] = "    " + line
+            else:
+                output[i] = "# %s" % line
+
+        out.writelines(output)
+
+
+parse_from_readme()