diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..e3a1888
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "cryptonum"]
+	path = cryptonum
+	url = https://github.com/acw/cryptonum.git
diff --git a/Cargo.toml b/Cargo.toml
index 83422c3..acc289e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,7 +11,7 @@ repository = "https://github.com/acw/simple_crypto"
 [dependencies]
 byteorder   = "^1.2.7"
 chrono      = "^0.4.6"
-cryptonum   = { path = "../cryptonum" }
+cryptonum   = { path = "cryptonum" }
 digest      = "^0.8.0"
 hmac        = "^0.7.0"
 num         = "^0.2.0"
diff --git a/cryptonum b/cryptonum
new file mode 160000
index 0000000..037413a
--- /dev/null
+++ b/cryptonum
@@ -0,0 +1 @@
+Subproject commit 037413ad15c9abc6159f41b64c2dab9660390278