diff --git a/.gitmodules b/.gitmodules
index 8e1e232..4076033 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -130,3 +130,6 @@
 [submodule "hashlib"]
 	path = hashlib
 	url = https://github.com/khchen/hashlib
+[submodule "noiseprotocol"]
+	path = noiseprotocol
+	url = https://git.sr.ht/~ehmry/noiseprotocol
diff --git a/noiseprotocol b/noiseprotocol
new file mode 160000
index 0000000..d6ff994
--- /dev/null
+++ b/noiseprotocol
@@ -0,0 +1 @@
+Subproject commit d6ff994c64d02cb57b5b52741bbe02d223720969