diff --git a/requirements.txt b/requirements.txt
index e030dd8..e4a344f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,3 +12,4 @@
 sphinxcontrib-blockdiag~=1.5.5
 sphinxcontrib-nwdiag~=0.9.5
 sphinxcontrib-seqdiag~=0.8.5
+git+https://github.com/leokoppel/sphinxcontrib-versioning