diff --git a/README.rst b/README.rst
index 781d66f..2adf0b8 100644
--- a/README.rst
+++ b/README.rst
@@ -71,9 +71,9 @@ References
 * Wavelet hashing (`wHashref`_)
 * Crop-resistant hashing (`crop_resistant_hashref`_)
 
-.. _aHashref: http://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
-.. _pHashref: http://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
-.. _dHashref: http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
+.. _aHashref: https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
+.. _pHashref: https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
+.. _dHashref: https://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
 .. _wHashref: https://fullstackml.com/2016/07/02/wavelet-image-hash-in-python/
 .. _pypi: https://pypi.python.org/pypi/ImageHash
 .. _crop_resistant_hashref: https://ieeexplore.ieee.org/document/6980335
@@ -102,7 +102,7 @@ You may want to adjust the hashsize or require some manhattan distance (hash1 -
 Example 2: Art dataset
 ----------------------
 
-Source: 109259 art pieces from http://parismuseescollections.paris.fr/en/recherche/image-libre/.
+Source: 109259 art pieces from https://www.parismuseescollections.paris.fr/en/recherche/image-libre/.
 
 The following pages show groups of images with the same hash (the hashing method sees them as the same).
 
diff --git a/imagehash/__init__.py b/imagehash/__init__.py
index bf9f644..e163255 100644
--- a/imagehash/__init__.py
+++ b/imagehash/__init__.py
@@ -234,7 +234,7 @@ def average_hash(image, hash_size=8, mean=numpy.mean):
 	"""
 	Average Hash computation
 
-	Implementation follows http://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
+	Implementation follows https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
 
 	Step by step explanation: https://web.archive.org/web/20171112054354/https://www.safaribooksonline.com/blog/2013/11/26/image-hashing-with-python/ # noqa: E501
 
@@ -262,7 +262,7 @@ def phash(image, hash_size=8, highfreq_factor=4):
 	"""
 	Perceptual Hash computation.
 
-	Implementation follows http://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
+	Implementation follows https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
 
 	@image must be a PIL instance.
 	"""
@@ -285,7 +285,7 @@ def phash_simple(image, hash_size=8, highfreq_factor=4):
 	"""
 	Perceptual Hash computation.
 
-	Implementation follows http://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
+	Implementation follows https://www.hackerfactor.com/blog/index.php?/archives/432-Looks-Like-It.html
 
 	@image must be a PIL instance.
 	"""
@@ -305,7 +305,7 @@ def dhash(image, hash_size=8):
 	"""
 	Difference Hash computation.
 
-	following http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
+	following https://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
 
 	computes differences horizontally
 
@@ -327,7 +327,7 @@ def dhash_vertical(image, hash_size=8):
 	"""
 	Difference Hash computation.
 
-	following http://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
+	following https://www.hackerfactor.com/blog/index.php?/archives/529-Kind-of-Like-That.html
 
 	computes differences vertically