diff --git a/requirements.txt b/requirements.txt
index a87cc86..eaf176b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -13,6 +13,7 @@ pycodestyle>=2.0.0
 pydocstyle
 pyensae
 pyinstrument
+pymmails
 pymyinstall
 pyquickhelper>=1.5.2175
 semantic_version