diff --git a/ci/macos/prepare.sh b/ci/macos/prepare.sh
index c7585e8f75..5e1efa0eef 100755
--- a/ci/macos/prepare.sh
+++ b/ci/macos/prepare.sh
@@ -6,5 +6,5 @@ set -e
 set -x
 
 brew update
-brew upgrade cmake openssl
+brew upgrade cmake openssl@1.1
 brew install swig bison