diff --git a/kokoro/macos/prepare_build_macos_rc b/kokoro/macos/prepare_build_macos_rc
index d94dd543fd5b..dcd17f330c12 100755
--- a/kokoro/macos/prepare_build_macos_rc
+++ b/kokoro/macos/prepare_build_macos_rc
@@ -45,6 +45,11 @@ sudo rm -rf \
 git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow
 git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-cask fetch --unshallow
 
+# This is needed to fix a conflict between the ilmbase and imath packages,
+# which seem to conflict with each other by both trying to install
+# libImath.dylib.
+brew unlink ilmbase
+
 brew update
 brew upgrade