diff --git a/.azure-pipelines/ci-conda-env.txt b/.azure-pipelines/ci-conda-env.txt
index bb73e6c19..15e08494e 100644
--- a/.azure-pipelines/ci-conda-env.txt
+++ b/.azure-pipelines/ci-conda-env.txt
@@ -22,7 +22,6 @@ conda-forge::orderedset
 conda-forge::pillow>=5.4.1
 conda-forge::pint
 conda-forge::pip
-conda-forge::procrunner
 conda-forge::psutil
 conda-forge::pyrtf
 conda-forge::pybind11
diff --git a/libtbx_config b/libtbx_config
index 0f9b1ae2e..e511ce2b2 100644
--- a/libtbx_config
+++ b/libtbx_config
@@ -3,7 +3,6 @@
     "python_required": [
         "dials-data>=2.0.30",
         "pint",
-        "procrunner>=1.0.2",
         "pytest>=4.5,<5.0",
     ],
 }
diff --git a/newsfragments/640.misc b/newsfragments/640.misc
new file mode 100644
index 000000000..8183d5860
--- /dev/null
+++ b/newsfragments/640.misc
@@ -0,0 +1 @@
+Use Python built-in ``subprocess`` in place of external dependency ``procrunner`` for running CLI tests.
diff --git a/tests/command_line/test_average.py b/tests/command_line/test_average.py
index 38d1c901e..bedbc2d48 100644
--- a/tests/command_line/test_average.py
+++ b/tests/command_line/test_average.py
@@ -1,13 +1,15 @@
 from __future__ import annotations
 
-import procrunner
+import shutil
+import subprocess
+
 import pytest
 
 import dxtbx
 
 
 @pytest.mark.parametrize("use_mpi", [True, False])
-def test_average(dials_data, tmpdir, use_mpi):
+def test_average(dials_data, tmp_path, use_mpi):
     # averager uses cbf handling code in the xfel module
     pytest.importorskip("xfel")
 
@@ -22,16 +24,16 @@ def test_average(dials_data, tmpdir, use_mpi):
         command = "mpirun"
         mpargs = "-n 2 dxtbx.image_average --mpi=True".split()
     else:
-        command = "dxtbx.image_average"
+        command = shutil.which("dxtbx.image_average")
         mpargs = "-n 2".split()
-    result = procrunner.run(
+    result = subprocess.run(
         [command] + mpargs + "-v -a avg.cbf -s stddev.cbf -m max.cbf".split() + [data],
-        working_directory=tmpdir,
+        cwd=tmp_path,
     )
     assert not result.returncode and not result.stderr
 
     h5 = dxtbx.load(data).get_detector()
-    cbf = dxtbx.load(tmpdir.join("avg.cbf")).get_detector()
+    cbf = dxtbx.load(tmp_path / "avg.cbf").get_detector()
 
     assert h5.is_similar_to(cbf)
     assert h5[0].get_gain() == cbf[0].get_gain()