diff --git a/src/_pytest/tmpdir.py b/src/_pytest/tmpdir.py
index c1e12da4f..ff3944dba 100644
--- a/src/_pytest/tmpdir.py
+++ b/src/_pytest/tmpdir.py
@@ -59,8 +59,8 @@ class TempPathFactory:
             Directory base name, must be a relative path.
 
         :param numbered:
-            If True, ensure the directory is unique by adding a number
-            prefix greater than any existing one: ``basename="foo"`` and ``numbered=True``
+            If ``True``, ensure the directory is unique by adding a numbered
+            suffix greater than any existing one: ``basename="foo-"`` and ``numbered=True``
             means that this function will create directories named ``"foo-0"``,
             ``"foo-1"``, ``"foo-2"`` and so on.