diff --git a/.gitmodules b/.gitmodules
index 09d6eaab2..e9812d1cb 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "test/Petalisp"]
 	path = test/Petalisp
 	url = https://github.com/marcoheisig/Petalisp.git
+[submodule "test/sly"]
+	path = test/sly
+	url = https://github.com/joaotavora/sly.git
diff --git a/test/sly b/test/sly
new file mode 160000
index 000000000..0470c0281
--- /dev/null
+++ b/test/sly
@@ -0,0 +1 @@
+Subproject commit 0470c0281498b9de072fcbf3718fc66720eeb3d0