diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca390b9..844262b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -73,7 +73,7 @@ Version 1.0.9 (Jan, 2017)
     - Added time bound to README. Addresses 
       [Issue #15](https://github.com/bmc/munkres/issues/15).
 - Versioning will now adhere to
-  [semantic version specification](http://semver.org).
+  [semantic version specification](https://semver.org).
 
 Version 1.0.8 (June, 2016)
 
diff --git a/LICENSE.md b/LICENSE.md
index 4687f9e..3aad37b 100644
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -4,7 +4,7 @@ Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
-  http://www.apache.org/licenses/LICENSE-2.0
+  https://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
diff --git a/README.md b/README.md
index 04b6092..fe8e168 100644
--- a/README.md
+++ b/README.md
@@ -19,9 +19,9 @@ from each row and column in the matrix, such that no row and no column are
 used more than once.
 
 This particular implementation is based on 
-<http://csclab.murraystate.edu/~bob.pilgrim/445/munkres.html>.
+<https://csclab.murraystate.edu/~bob.pilgrim/445/munkres.html>.
 
-[Hungarian algorithm]: http://en.wikipedia.org/wiki/Hungarian_algorithm
+[Hungarian algorithm]: https://en.wikipedia.org/wiki/Hungarian_algorithm
 
 See the docs on the [project page][] for more details.
 
@@ -30,7 +30,7 @@ If you need to use this package with Python 2, install an earlier version.
 See [the installation instructions](http://software.clapper.org/munkres/#installing) 
 for details.
 
-[project page]: http://software.clapper.org/munkres/
+[project page]: https://software.clapper.org/munkres/
 
 ## Copyright
 
diff --git a/munkres.py b/munkres.py
index 22424cc..c774d39 100644
--- a/munkres.py
+++ b/munkres.py
@@ -6,7 +6,7 @@
 (also called the Hungarian algorithm or the Kuhn-Munkres algorithm),
 useful for solving the Assignment Problem.
 
-For complete usage documentation, see: http://software.clapper.org/munkres/
+For complete usage documentation, see: https://software.clapper.org/munkres/
 """
 
 __docformat__ = 'markdown'
@@ -35,7 +35,7 @@
 # Info about the module
 __version__   = "1.1.2"
 __author__    = "Brian Clapper, bmc@clapper.org"
-__url__       = "http://software.clapper.org/munkres/"
+__url__       = "https://software.clapper.org/munkres/"
 __copyright__ = "(c) 2008-2019 Brian M. Clapper"
 __license__   = "Apache Software License"