--- scipy/optimize/minpack.py-prev	2017-04-10 20:10:35.252918140 -0400
+++ scipy/optimize/minpack.py	2017-04-10 20:11:32.605216345 -0400
@@ -56,9 +56,10 @@
 
     Parameters
     ----------
     func : callable ``f(x, *args)``
-        A function that takes at least one (possibly vector) argument.
+        A function that takes at least one (possibly vector) argument,
+        and returns a value of the same length.
     x0 : ndarray
         The starting estimate for the roots of ``func(x) = 0``.
     args : tuple, optional
         Any extra arguments to `func`.