diff --git a/brainglobe_utils/general/pathlib.py b/brainglobe_utils/general/pathlib.py
index 0f5845d..1f90e85 100644
--- a/brainglobe_utils/general/pathlib.py
+++ b/brainglobe_utils/general/pathlib.py
@@ -1,4 +1,10 @@
-def append_to_pathlib_stem(path, string_to_append):
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+def append_to_pathlib_stem(path: "Path", string_to_append):
     """
     Appends a string to the stem of a pathlib object.
 
diff --git a/brainglobe_utils/general/string.py b/brainglobe_utils/general/string.py
index b7702de..7663ad3 100644
--- a/brainglobe_utils/general/string.py
+++ b/brainglobe_utils/general/string.py
@@ -1,15 +1,20 @@
+from typing import TYPE_CHECKING, Optional
+
 from natsort import natsorted
 
 from brainglobe_utils.general import list
 
+if TYPE_CHECKING:
+    from pathlib import Path
+
 
 def get_text_lines(
-    file,
-    return_lines=None,
-    rstrip=True,
-    sort=False,
-    remove_empty_lines=True,
-    encoding="utf8",
+    file: "Path",
+    return_lines: Optional[int] = None,
+    rstrip: Optional[bool] = True,
+    sort: Optional[bool] = False,
+    remove_empty_lines: Optional[bool] = True,
+    encoding: Optional[str] = "utf8",
 ):
     """
     Return only the nth line of a text file.