diff --git a/Doc/tutorial/floatingpoint.rst b/Doc/tutorial/floatingpoint.rst
index b98de6e56a0..7212b40be83 100644
--- a/Doc/tutorial/floatingpoint.rst
+++ b/Doc/tutorial/floatingpoint.rst
@@ -133,7 +133,7 @@ with inexact values become comparable to one another::
 
 Binary floating-point arithmetic holds many surprises like this.  The problem
 with "0.1" is explained in precise detail below, in the "Representation Error"
-section.  See `The Perils of Floating Point <http://www.lahey.com/float.htm>`_
+section.  See `The Perils of Floating Point <https://www.lahey.com/float.htm>`_
 for a more complete account of other common surprises.
 
 As that says near the end, "there are no easy answers."  Still, don't be unduly