diff --git a/.gitmodules b/.gitmodules
index 9e337454e..aed2ac128 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -21,3 +21,6 @@
 [submodule "OpenKeychain/src/test/resources/openpgp-interop"]
 	path = OpenKeychain/src/test/resources/openpgp-interop
 	url = https://github.com/google/openpgp-interop
+[submodule "extern/bouncycastle"]
+	path = extern/bouncycastle
+	url = https://github.com/open-keychain/bouncycastle.git
diff --git a/extern/bouncycastle b/extern/bouncycastle
new file mode 160000
index 000000000..9b11b73f6
--- /dev/null
+++ b/extern/bouncycastle
@@ -0,0 +1 @@
+Subproject commit 9b11b73f6eb1476e2f7c2b066b2130d32e3b72f7