diff --git a/python/binharness/agentenvironment.py b/python/binharness/agentenvironment.py
index 8b24498..4f6e4ee 100644
--- a/python/binharness/agentenvironment.py
+++ b/python/binharness/agentenvironment.py
@@ -115,22 +115,31 @@ def __init__(  # noqa: PLR0913
         self._pid = pid
 
     @cached_property
-    def stdin(self: AgentProcess) -> AgentIO:
+    def stdin(self: AgentProcess) -> AgentIO | None:
         """Get the standard input stream of the process."""
-        fd = self._client.get_process_channel(self._env_id, self._pid, 0)
-        return AgentIO(self._client, self._env_id, fd)
+        try:
+            fd = self._client.get_process_channel(self._env_id, self._pid, 0)
+            return AgentIO(self._client, self._env_id, fd)
+        except RuntimeError:
+            return None  # TODO: verify that this is the right error
 
     @cached_property
-    def stdout(self: AgentProcess) -> AgentIO:
+    def stdout(self: AgentProcess) -> AgentIO | None:
         """Get the standard output stream of the process."""
-        fd = self._client.get_process_channel(self._env_id, self._pid, 1)
-        return AgentIO(self._client, self._env_id, fd)
+        try:
+            fd = self._client.get_process_channel(self._env_id, self._pid, 1)
+            return AgentIO(self._client, self._env_id, fd)
+        except RuntimeError:
+            return None  # TODO: verify that this is the right error
 
     @cached_property
-    def stderr(self: AgentProcess) -> AgentIO:
+    def stderr(self: AgentProcess) -> AgentIO | None:
         """Get the standard error stream of the process."""
-        fd = self._client.get_process_channel(self._env_id, self._pid, 2)
-        return AgentIO(self._client, self._env_id, fd)
+        try:
+            fd = self._client.get_process_channel(self._env_id, self._pid, 2)
+            return AgentIO(self._client, self._env_id, fd)
+        except RuntimeError:
+            return None  # TODO: verify that this is the right error
 
     @property
     def returncode(self: AgentProcess) -> int | None:
@@ -174,7 +183,7 @@ def run_command(
             stdin=True,
             stdout=True,
             stderr=True,
-            executable=str(args[0]),
+            executable=str(normalized_args[0]),
             env=list(env.items()) if env else None,
             cwd=str(cwd) if cwd else None,
             setuid=None,
diff --git a/python/binharness/common/busybox.py b/python/binharness/common/busybox.py
index a013fcb..f4193fa 100644
--- a/python/binharness/common/busybox.py
+++ b/python/binharness/common/busybox.py
@@ -4,7 +4,7 @@
 
 from os import environ
 from pathlib import Path
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, cast
 
 from binharness.types import InjectableExecutor, Target
 from binharness.types.injection import ExecutableInjection
@@ -48,7 +48,8 @@ def mktemp(
         """Run mktemp in the environment and returns the Path created."""
         proc = self.run("mktemp", "-d") if directory else self.run("mktemp")
         stdout, _ = proc.communicate()
-        return Path(stdout.decode().strip())
+        # TODO: Find out how to not cast
+        return Path(cast(bytes, stdout).decode().strip())
 
     def shell(
         self: BusyboxInjection, command: str, env: dict[str, str] | None = None
diff --git a/python/binharness/localenvironment.py b/python/binharness/localenvironment.py
index a4f822a..988034f 100644
--- a/python/binharness/localenvironment.py
+++ b/python/binharness/localenvironment.py
@@ -110,24 +110,18 @@ def __init__(
         )
 
     @property
-    def stdin(self: LocalProcess) -> IO[bytes]:
+    def stdin(self: LocalProcess) -> IO[bytes] | None:
         """Get the standard input stream of the process."""
-        if self.popen.stdin is None:
-            raise ValueError  # pragma: no cover
         return self.popen.stdin
 
     @property
-    def stdout(self: LocalProcess) -> IO[bytes]:
+    def stdout(self: LocalProcess) -> IO[bytes] | None:
         """Get the standard output stream of the process."""
-        if self.popen.stdout is None:
-            raise ValueError  # pragma: no cover
         return self.popen.stdout
 
     @property
-    def stderr(self: LocalProcess) -> IO[bytes]:
+    def stderr(self: LocalProcess) -> IO[bytes] | None:
         """Get the standard error stream of the process."""
-        if self.popen.stderr is None:
-            raise ValueError  # pragma: no cover
         return self.popen.stderr
 
     @property
diff --git a/python/binharness/types/process.py b/python/binharness/types/process.py
index 168b3bb..d676638 100644
--- a/python/binharness/types/process.py
+++ b/python/binharness/types/process.py
@@ -34,17 +34,17 @@ def __init__(
         self.cwd = cwd or environment.get_tempdir()
 
     @abstractproperty
-    def stdin(self: Process) -> IO[bytes]:
+    def stdin(self: Process) -> IO[bytes] | None:
         """Get the standard input stream of the process."""
         raise NotImplementedError
 
     @abstractproperty
-    def stdout(self: Process) -> IO[bytes]:
+    def stdout(self: Process) -> IO[bytes] | None:
         """Get the standard output stream of the process."""
         raise NotImplementedError
 
     @abstractproperty
-    def stderr(self: Process) -> IO[bytes]:
+    def stderr(self: Process) -> IO[bytes] | None:
         """Get the standard error stream of the process."""
         raise NotImplementedError
 
@@ -65,10 +65,13 @@ def wait(self: Process, timeout: float | None = None) -> int:
 
     def communicate(
         self: Process, input_: bytes | None = None, timeout: float | None = None
-    ) -> tuple[bytes, bytes]:
+    ) -> tuple[bytes | None, bytes | None]:
         """Send input to the process and return its output and error streams."""
-        if input_ is not None:
-            self.stdin.write(input_)
-        self.stdin.close()
+        if self.stdin is not None:
+            if input_ is not None:
+                self.stdin.write(input_)
+            self.stdin.close()
         self.wait(timeout)
-        return (self.stdout.read(), self.stderr.read())
+        stdout = self.stdout.read() if self.stdout is not None else None
+        stderr = self.stderr.read() if self.stderr is not None else None
+        return (stdout, stderr)
diff --git a/python/tests/bootstrap/test_docker.py b/python/tests/bootstrap/test_docker.py
index 062952d..d0f2559 100644
--- a/python/tests/bootstrap/test_docker.py
+++ b/python/tests/bootstrap/test_docker.py
@@ -27,6 +27,7 @@ def test_bootstrap_env_from_image(
 
         proc.wait()
         assert proc.returncode == 0
+        assert proc.stdout is not None
         assert proc.stdout.read() == b"hello world\n"
     finally:
         agent.container.kill()
diff --git a/python/tests/bootstrap/test_ssh.py b/python/tests/bootstrap/test_ssh.py
index 90aa186..06487c3 100644
--- a/python/tests/bootstrap/test_ssh.py
+++ b/python/tests/bootstrap/test_ssh.py
@@ -47,6 +47,7 @@ def test_bootstrap_ssh_environment_with_client(
 
         proc.wait()
         assert proc.returncode == 0
+        assert proc.stdout is not None
         assert proc.stdout.read() == b"hello world\n"
     finally:
         agent.stop()
diff --git a/python/tests/test_busybox.py b/python/tests/test_busybox.py
index d0e55e9..58de298 100644
--- a/python/tests/test_busybox.py
+++ b/python/tests/test_busybox.py
@@ -43,10 +43,14 @@ def test_nc_interaction() -> None:
     server_proc = busybox.nc("localhost", 10001, listen=True)
     client_proc = busybox.nc("localhost", 10001)
 
+    assert client_proc.stdin is not None
+    assert server_proc.stdin is not None
     client_proc.stdin.write(b"hello\n")
     client_proc.stdin.flush()
     server_proc.stdin.write(b"hello back\n")
     server_proc.stdin.flush()
 
+    assert server_proc.stdout is not None
     assert server_proc.stdout.readline() == b"hello\n"
+    assert client_proc.stdout is not None
     assert client_proc.stdout.readline() == b"hello back\n"
diff --git a/python/tests/test_localenvironment.py b/python/tests/test_localenvironment.py
index 00d7c70..fc968a0 100644
--- a/python/tests/test_localenvironment.py
+++ b/python/tests/test_localenvironment.py
@@ -43,6 +43,7 @@ def test_stdout() -> None:
     busybox = BusyboxInjection()
     busybox.install(env)
     proc = busybox.shell("echo hello")
+    assert proc.stdout is not None
     assert proc.stdout.read() == b"hello\n"
 
 
@@ -52,6 +53,7 @@ def test_stderr() -> None:
     busybox = BusyboxInjection()
     busybox.install(env)
     proc = busybox.shell("echo hello 1>&2")
+    assert proc.stderr is not None
     assert proc.stderr.read() == b"hello\n"
 
 
@@ -62,8 +64,10 @@ def test_process_poll() -> None:
     busybox.install(env)
     proc = busybox.run("head")
     assert proc.poll() is None
+    assert proc.stdin is not None
     proc.stdin.write(b"hello\n")
     proc.stdin.close()
     proc.wait()
     assert proc.poll() is not None
+    assert proc.stdout is not None
     assert proc.stdout.read() == b"hello\n"