diff --git a/.gitmodules b/.gitmodules
index ed4e5ba..27abc9e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -9,3 +9,6 @@
 [submodule "lib/openzeppelin-contracts"]
 	path = lib/openzeppelin-contracts
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts
+[submodule "lib/openzeppelin-contracts-upgradeable"]
+	path = lib/openzeppelin-contracts-upgradeable
+	url = https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable
diff --git a/lib/openzeppelin-contracts-upgradeable b/lib/openzeppelin-contracts-upgradeable
new file mode 160000
index 0000000..3d4c0d5
--- /dev/null
+++ b/lib/openzeppelin-contracts-upgradeable
@@ -0,0 +1 @@
+Subproject commit 3d4c0d5741b131c231e558d7a6213392ab3672a5