diff --git a/travis/install_grpc.sh b/travis/install_grpc.sh
index 0ff7468030f..9810f2259e2 100755
--- a/travis/install_grpc.sh
+++ b/travis/install_grpc.sh
@@ -41,7 +41,10 @@ if [ `uname -s` == "Darwin" ]; then
   export GRPC_PYTHON_BUILD_WITH_CYTHON=1
   $grpc_dist/usr/local/bin/pip install Cython
 
-  # this enables to build protobuf on OSX Sierra
+  # Work-around macOS Sierra blocker, see: https://github.com/youtube/vitess/issues/2115
+  # TODO(mberlin): Remove this when the underlying issue is fixed and available
+  #                in the gRPC version used by Vitess.
+  #                See: https://github.com/google/protobuf/issues/2182
   export CPPFLAGS="-Wno-deprecated-declarations"
 fi