diff --git a/.gitmodules b/.gitmodules
index 3576722..ceed45f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,15 +1,20 @@
 [submodule "boringssl"]
 	path = third_party/boringssl/src
 	url = https://pigweed.googlesource.com/third_party/boringssl/boringssl
+	branch = main
 [submodule "mbedtls"]
 	path = third_party/mbedtls/src
 	url = https://pigweed.googlesource.com/third_party/github/ARMmbed/mbedtls.git
+	branch = main
 [submodule "cn-cbor"]
 	path = third_party/cn-cbor/src
 	url = https://pigweed.googlesource.com/third_party/github/jimsch/cn-cbor.git
+	branch = main
 [submodule "cose-c"]
 	path = third_party/cose-c/src
 	url = https://pigweed.googlesource.com/third_party/github/cose-wg/COSE-C.git
+	branch = main
 [submodule "pigweed"]
 	path = third_party/pigweed/src
 	url = https://pigweed.googlesource.com/pigweed/pigweed
+	branch = main