diff --git a/third_party/protobuf b/third_party/protobuf
index 3afcded28a6..97d50e306e5 160000
--- a/third_party/protobuf
+++ b/third_party/protobuf
@@ -1 +1 @@
-Subproject commit 3afcded28a6aa9c44adf801ca5bff2133fcf3030
+Subproject commit 97d50e306e576dadf2184e643b7c934da45730c8
diff --git a/tools/run_tests/sanity/check_submodules.sh b/tools/run_tests/sanity/check_submodules.sh
index 763b7085e30..569aaded038 100755
--- a/tools/run_tests/sanity/check_submodules.sh
+++ b/tools/run_tests/sanity/check_submodules.sh
@@ -31,7 +31,7 @@ cat << EOF | awk '{ print $1 }' | sort > $want_submodules
  886e7d75368e3f4fab3f4d0d3584e4abfc557755 third_party/boringssl-with-bazel (version_for_cocoapods_7.0-857-g886e7d7)
  30dbc81fb5ffdc98ea9b14b1918bfe4e8779b26e third_party/gflags (v2.2.0)
  ec44c6c1675c25b9827aacd08c02433cccde7780 third_party/googletest (release-1.8.0)
- 3afcded28a6aa9c44adf801ca5bff2133fcf3030 third_party/protobuf (v3.4.0rc1)
+ 97d50e306e576dadf2184e643b7c934da45730c8 third_party/protobuf (v3.4.0rc2)
  cacf7f1d4e3d44d871b605da3b647f07d718623f third_party/zlib (v1.2.11)
  7691f773af79bf75a62d1863fd0f13ebf9dc51b1 third_party/cares/cares (1.12.0)
 EOF