diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..c2fbd5b
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "hdbscan_issue_demo"]
+	path = hdbscan_issue_demo
+	url = https://github.com/emilyhunt/hdbscan_issue_demo
diff --git a/hdbscan_issue_demo b/hdbscan_issue_demo
new file mode 160000
index 0000000..604dc20
--- /dev/null
+++ b/hdbscan_issue_demo
@@ -0,0 +1 @@
+Subproject commit 604dc20aacbb170adf5fa9ec6394c3247d242a87