diff --git a/docs/random-numbers.rst b/docs/random-numbers.rst
index 5f94bf1..8c6b9fd 100644
--- a/docs/random-numbers.rst
+++ b/docs/random-numbers.rst
@@ -29,4 +29,4 @@
 
     >>> serial = int.from_bytes(os.urandom(20), byteorder="big")
 
-.. _`always use your operating system's provided random number generator`: http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/
+.. _`always use your operating system's provided random number generator`: https://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/