diff --git a/kokoro/macos/prepare_build_macos_rc b/kokoro/macos/prepare_build_macos_rc
index 13b00706756f..9b9b2df7b88c 100755
--- a/kokoro/macos/prepare_build_macos_rc
+++ b/kokoro/macos/prepare_build_macos_rc
@@ -6,6 +6,10 @@ set -eux
 
 export HOMEBREW_PREFIX=$(brew --prefix)
 
+##
+# Remove any pre-existing protobuf installation.
+brew uninstall protobuf
+
 ##
 # Select Xcode version
 
diff --git a/kokoro/release/python/macos/build_artifacts.sh b/kokoro/release/python/macos/build_artifacts.sh
index fbbd650b71c7..1b3815eeaf90 100755
--- a/kokoro/release/python/macos/build_artifacts.sh
+++ b/kokoro/release/python/macos/build_artifacts.sh
@@ -2,6 +2,9 @@
 
 set -ex
 
+# Remove any pre-existing protobuf installation.
+brew uninstall protobuf
+
 # change to repo root
 pushd $(dirname $0)/../../../..