diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
index a909b856951e..32be7c1b4aad 100644
--- a/lib/matplotlib/widgets.py
+++ b/lib/matplotlib/widgets.py
@@ -945,7 +945,7 @@ def on_changed(self, func):
         ----------
         func : callable
             Function to call when slider is changed. The function
-            must accept a numpy array with shape (2,) as its argument.
+            must accept a 2-tuple of floats as its argument.
 
         Returns
         -------