diff --git a/pyproject.toml b/pyproject.toml
index 3e1299417d03784129bfda9d53ca58046619cf5d..b67fac677676e140a82ea8cdaf3b881e370e202a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,6 +54,11 @@ django-yarnpkg = "^6.0"
 django-dbsettings = "^0.11.0"
 
 [tool.poetry.extras]
+app-alsijil = ['BiscuIT-App-Alsijil']
+app-chronos = ['BiscuIT-App-Chronos']
+app-exlibris = ['BiscuIT-App-Exlibris']
+app-schild-nrw = ['BiscuIT-App-SchILD-NRW']
+app-untis = ['BiscuIT-App-Untis']
 ldap = ["django-auth-ldap"]
 
 [tool.poetry.dev-dependencies]