diff --git a/python/tskit/trees.py b/python/tskit/trees.py
index cd08c40c2f..85ea7934d8 100644
--- a/python/tskit/trees.py
+++ b/python/tskit/trees.py
@@ -9328,8 +9328,8 @@ def pair_coalescence_counts(
             sequence windows to compute the statistic in, or None.
         :param bool span_normalise: Whether to divide the result by the span of
             the window (defaults to True).
-        :param time_windows: Either a string "nodes" or an increasing
-            list of breakpoints between time intervals.
+        :param time_windows: Either "nodes" or an increasing list of
+            breakpoints between time intervals.
         """
 
         if sample_sets is None: