diff --git a/behave_utils/proc.py b/behave_utils/proc.py
index fc9d08f23d0c580f09f7962614b4db818daf96f7..c29bdeb09bae2828b0a2e69c9b44c1e14a6fe7b5 100644
--- a/behave_utils/proc.py
+++ b/behave_utils/proc.py
@@ -170,10 +170,11 @@ async def _exec_io(
 	kwargs: dict[str, Any],
 ) -> trio.Process:
 	async with trio.open_nursery() as nursery:
+		stdin = kwargs.pop('stdin') if 'stdin' in kwargs else PIPE if data else DEVNULL
 		proc: trio.Process = await nursery.start(
 			partial(
 				trio.run_process, [*coerce_args(cmd)],
-				stdin=PIPE if data else DEVNULL,
+				stdin=stdin,
 				stdout=PIPE, stderr=PIPE,
 				check=False,
 				**kwargs,
diff --git a/tests/unit/proc/test_async.py b/tests/unit/proc/test_async.py
index 43363f93bb2a7cdd4bcc4d9f9d88023a510c5f22..866b568933481d4b896fcb37f7cf8a9a3410e82a 100644
--- a/tests/unit/proc/test_async.py
+++ b/tests/unit/proc/test_async.py
@@ -71,6 +71,33 @@ class ExecIOTests(TestCase):
 		with self.assertRaises(TypeError):
 			await proc.aexec_io(ECHO_OUTPUT, input=TEST_BYTES, stdin=sys.stdin)
 
+	@trio_test()
+	async def test_stdin(self) -> None:
+		"""
+		Check that calling with the "stdin" argument works as expected
+
+		Regression test for #22
+		"""
+		with self.subTest(stdin="IO[bytes]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "rb") as pipe:
+				recv = await proc.aexec_io(ECHO_OUTPUT, stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
+		with self.subTest(stdin="IO[str]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "r") as pipe:
+				recv = await proc.aexec_io(ECHO_OUTPUT, stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
 	@trio_test()
 	async def test_stdout(self) -> None:
 		"""
@@ -136,6 +163,35 @@ class ExecutorTests(TestCase):
 
 		self.assertEqual(output, TEST_BYTES)
 
+	@trio_test()
+	async def test_stdin(self) -> None:
+		"""
+		Check that calling with the "stdin" argument works as expected
+
+		Regression test for #22
+		"""
+		exe = proc.AsyncExecutor(*FIXTURE_CMD)
+
+		with self.subTest(stdin="IO[bytes]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "rb") as pipe:
+				recv = await exe("echo", stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
+		with self.subTest(stdin="IO[str]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "r") as pipe:
+				recv = await exe("echo", stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
 	@trio_test()
 	async def test_stdout(self) -> None:
 		"""
diff --git a/tests/unit/proc/test_proc.py b/tests/unit/proc/test_proc.py
index e7b486839623376d79deab6753d55c6db529edcf..884849f5a06ec388e3e13928f8630acddf871f75 100644
--- a/tests/unit/proc/test_proc.py
+++ b/tests/unit/proc/test_proc.py
@@ -88,6 +88,32 @@ class ExecIOTests(TestCase):
 		with self.assertRaises(TypeError):
 			proc.exec_io(ECHO_OUTPUT, input=TEST_BYTES, stdin=sys.stdin)
 
+	def test_stdin(self) -> None:
+		"""
+		Check that calling with the "stdin" argument works as expected
+
+		Regression test for #22
+		"""
+		with self.subTest(stdin="IO[bytes]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "rb") as pipe:
+				recv = proc.exec_io(ECHO_OUTPUT, stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
+		with self.subTest(stdin="IO[str]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "r") as pipe:
+				recv = proc.exec_io(ECHO_OUTPUT, stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
 	def test_stdout(self) -> None:
 		"""
 		Check that calling with the "stdout" argument receives bytes from stdout
@@ -158,6 +184,34 @@ class ExecutorTests(TestCase):
 
 		self.assertEqual(output, TEST_BYTES)
 
+	def test_stdin(self) -> None:
+		"""
+		Check that calling with the "stdin" argument works as expected
+
+		Regression test for #22
+		"""
+		exe = proc.Executor(*FIXTURE_CMD)
+
+		with self.subTest(stdin="IO[bytes]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "rb") as pipe:
+				recv = exe("echo", stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
+		with self.subTest(stdin="IO[str]"):
+			rfd, wfd = os.pipe()
+			with open(wfd, "wb") as pipe:
+				pipe.write(TEST_BYTES)
+
+			with open(rfd, "r") as pipe:
+				recv = exe("echo", stdin=pipe, deserialiser=bytes)
+
+			self.assertEqual(recv, TEST_BYTES)
+
 	def test_stdout(self) -> None:
 		"""
 		Check that calling with the "stdout" argument receives bytes from stdout