diff --git a/.gitmodules b/.gitmodules
index 7e00da228..68faaf9fd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -14,3 +14,6 @@
 [submodule "external/miniupnp"]
 	path = external/miniupnp
 	url = https://github.com/miniupnp/miniupnp
+[submodule "external/mx25519"]
+    path = external/mx25519
+    url = https://github.com/tevador/mx25519