diff --git a/kokoro/macos/prepare_build_macos_rc b/kokoro/macos/prepare_build_macos_rc
index 75b50c09f93c..8f99f105face 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 a72ee6733f1c..296bd9aef399 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)/../../../..