diff --git a/skimage/filter/thresholding.py b/skimage/filter/thresholding.py
index 0e908604..3985e278 100644
--- a/skimage/filter/thresholding.py
+++ b/skimage/filter/thresholding.py
@@ -220,7 +220,7 @@ def threshold_isodata(image, nbins=256, return_all=False):
 
     Returns
     -------
-    threshold : float, int, array
+    threshold : float or int or array
         Threshold value(s).
 
     References