diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..9f59da3d
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "build-aux/shared-modules"]
+	path = build-aux/shared-modules
+	url = https://github.com/flathub/shared-modules
diff --git a/build-aux/org.gnome.Calendar.json b/build-aux/org.gnome.Calendar.json
index 8b75ff2e..6483efaf 100644
--- a/build-aux/org.gnome.Calendar.json
+++ b/build-aux/org.gnome.Calendar.json
@@ -116,17 +116,7 @@
                 }
             ]
         },
-        {
-            "name": "intltool",
-            "cleanup": [ "*" ],
-            "sources": [
-                {
-                    "type": "archive",
-                    "url": "https://launchpad.net/intltool/trunk/0.51.0/+download/intltool-0.51.0.tar.gz",
-                    "sha256": "67c74d94196b153b774ab9f89b2fa6c6ba79352407037c8c14d5aeb334e959cd"
-                }
-            ]
-        },
+        "shared-modules/intltool/intltool-0.51.json",
         {
             "name" : "gcr",
             "buildsystem" : "meson",
diff --git a/build-aux/shared-modules b/build-aux/shared-modules
new file mode 160000
index 00000000..2dfad855
--- /dev/null
+++ b/build-aux/shared-modules
@@ -0,0 +1 @@
+Subproject commit 2dfad855131c70ff7cafd32f3f4901c6d82b9247