diff --git a/pyproject.toml b/pyproject.toml
index 926b62045c..37e4161032 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -56,6 +56,7 @@ warn_unused_configs = true
 
 [[tool.mypy.overrides]]
 module = [
+    "src.archivematicaCommon.lib.executeOrRunSubProcess",
     "src.MCPClient.lib.client.*",
     "src.MCPClient.lib.clientScripts.characterize_file",
     "src.MCPClient.lib.clientScripts.has_packages",
diff --git a/src/archivematicaCommon/lib/executeOrRunSubProcess.py b/src/archivematicaCommon/lib/executeOrRunSubProcess.py
index b23bcfaedc..b7aff8d3c5 100644
--- a/src/archivematicaCommon/lib/executeOrRunSubProcess.py
+++ b/src/archivematicaCommon/lib/executeOrRunSubProcess.py
@@ -21,18 +21,29 @@
 import subprocess
 import sys
 import tempfile
+from typing import Dict
+from typing import List
+from typing import Optional
+from typing import Tuple
+from typing import Union
 
 from archivematicaFunctions import escape
 
+Arguments = List[str]
+Input = Union[str, bytes, io.IOBase]
+Environment = Dict[str, str]
+Command = Union[str, List[str]]
+Result = Tuple[int, str, str]
+
 
 def launchSubProcess(
-    command,
-    stdIn="",
-    printing=True,
-    arguments=None,
-    env_updates=None,
-    capture_output=False,
-):
+    command: Command,
+    stdIn: Input = "",
+    printing: bool = True,
+    arguments: Optional[Arguments] = None,
+    env_updates: Optional[Environment] = None,
+    capture_output: bool = False,
+) -> Result:
     """
     Launches a subprocess using ``command``, where ``command`` is either:
     a) a single string containing a commandline statement, or
@@ -91,7 +102,7 @@ def launchSubProcess(
             stdin_pipe = subprocess.PIPE
             communicate_input = stdIn
         elif isinstance(stdIn, io.IOBase):
-            stdin_pipe = stdIn
+            stdin_pipe = stdIn.fileno()
             communicate_input = None
         else:
             raise Exception("stdIn must be a string or a file object")
@@ -141,8 +152,13 @@ def launchSubProcess(
 
 
 def createAndRunScript(
-    text, stdIn="", printing=True, arguments=None, env_updates=None, capture_output=True
-):
+    text: Command,
+    stdIn: Input = "",
+    printing: bool = True,
+    arguments: Optional[Arguments] = None,
+    env_updates: Optional[Environment] = None,
+    capture_output: bool = True,
+) -> Result:
     if arguments is None:
         arguments = []
     if env_updates is None:
@@ -152,7 +168,10 @@ def createAndRunScript(
         encoding="utf-8", mode="wt", delete=False
     ) as tmpfile:
         os.chmod(tmpfile.name, 0o770)
-        tmpfile.write(text)
+        if isinstance(text, str):
+            tmpfile.write(text)
+        else:
+            tmpfile.write(" ".join(text))
         tmpfile.close()
         cmd = [tmpfile.name]
         cmd.extend(arguments)
@@ -170,14 +189,14 @@ def createAndRunScript(
 
 
 def executeOrRun(
-    type,
-    text,
-    stdIn="",
-    printing=True,
-    arguments=None,
-    env_updates=None,
-    capture_output=True,
-):
+    type: str,
+    text: Command,
+    stdIn: Input = "",
+    printing: bool = True,
+    arguments: Optional[Arguments] = None,
+    env_updates: Optional[Environment] = None,
+    capture_output: bool = True,
+) -> Result:
     """
     Attempts to run the provided command on the shell, with the text of
     "stdIn" passed as standard input if provided. The type parameter
@@ -222,7 +241,7 @@ def executeOrRun(
             capture_output=capture_output,
         )
     if type == "bashScript":
-        text = "#!/bin/bash\n" + text
+        text = rf"#!/bin/bash\n{text}"
         return createAndRunScript(
             text,
             stdIn=stdIn,
@@ -232,7 +251,7 @@ def executeOrRun(
             capture_output=capture_output,
         )
     if type == "pythonScript":
-        text = "#!/usr/bin/env python\n" + text
+        text = rf"#!/usr/bin/env python\n{text}"
         return createAndRunScript(
             text,
             stdIn=stdIn,
@@ -250,3 +269,4 @@ def executeOrRun(
             env_updates=env_updates,
             capture_output=capture_output,
         )
+    raise ValueError(f"unknown type {type}")