diff --git a/.gitmodules b/.gitmodules
index 68ea45db..475aa891 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -846,3 +846,6 @@
 [submodule "repos/NullSet"]
 	path = repos/NullSet
 	url = https://github.com/nicholas-j-denning/NullSet.git
+[submodule "repos/Calvario"]
+	path = repos/Calvario
+	url = https://github.com/HydrangeaSystems/Calvario
diff --git a/repos/Calvario b/repos/Calvario
new file mode 160000
index 00000000..db7930d8
--- /dev/null
+++ b/repos/Calvario
@@ -0,0 +1 @@
+Subproject commit db7930d8b8f5818ece365f7409d5b67ee2f93d70