diff --git a/doc/buildsystem.rst b/doc/buildsystem.rst
index df28ce02585ae1557e4af1d57b2d942fb396ea51..0a3449d5f69d1f3c408cce53b3b765d8fab340cd 100644
--- a/doc/buildsystem.rst
+++ b/doc/buildsystem.rst
@@ -165,7 +165,7 @@ safely delete the whole source folder.
 .. _python: https://www.python.org/
 .. _boost: https://www.boost.org/
 .. _eigen3: http://eigen.tuxfamily.org/index.php?title=Main_Page
-.. _openmm: http://openmm.org
+.. _openmm: https://github.com/openmm/openmm
 
 ..  LocalWords:  cmake makefiles CMakeLists txt DOCTEST LINKCHECK conf html
 ..  LocalWords:  doctest linkcheck qmean DQMEAN eigen CMakeCache