diff --git a/AUTHORS b/AUTHORS
index daa6a471eb9..ae04e587921 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -8,6 +8,7 @@ Abdeali JK
 Abdelrahman Elbehery
 Abhijeet Kasurde
 ace2016
+Adam Dangoor
 Adam Johnson
 Adam Stewart
 Adam Uhlir
diff --git a/changelog/14988.improvement.rst b/changelog/14988.improvement.rst
new file mode 100644
index 00000000000..724425456e0
--- /dev/null
+++ b/changelog/14988.improvement.rst
@@ -0,0 +1 @@
+:meth:`MonkeyPatch.syspath_prepend <pytest.MonkeyPatch.syspath_prepend>` now annotates its ``path`` parameter as ``str | os.PathLike[str]``, so strict type checkers no longer report calls to it as having an unknown type.
diff --git a/src/_pytest/monkeypatch.py b/src/_pytest/monkeypatch.py
index 453c6728ee2..d4f5695be9e 100644
--- a/src/_pytest/monkeypatch.py
+++ b/src/_pytest/monkeypatch.py
@@ -360,7 +360,7 @@ def delenv(self, name: str, raising: bool = True) -> None:
         environ: MutableMapping[str, str] = os.environ
         self.delitem(environ, name, raising=raising)
 
-    def syspath_prepend(self, path) -> None:
+    def syspath_prepend(self, path: str | os.PathLike[str]) -> None:
         """Prepend ``path`` to ``sys.path`` list of import locations."""
         if self._savesyspath is None:
             self._savesyspath = sys.path[:]