diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 24bf86147d3e1..01f817300a01a 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -1102,7 +1102,7 @@ def to_string(
         ...
 
     @Substitution(
-        header_type="bool or sequence of strings",
+        header_type="bool or sequence of str",
         header="Write out the column names. If a list of strings "
         "is given, it is assumed to be aliases for the "
         "column names",