diff --git a/.ci/scripts/setup-macos.sh b/.ci/scripts/setup-macos.sh
index 833ba0aafe6..b1a8ff14b57 100755
--- a/.ci/scripts/setup-macos.sh
+++ b/.ci/scripts/setup-macos.sh
@@ -49,6 +49,9 @@ install_buck() {
 
   rm "${BUCK2}"
   popd
+
+  # Kill all running buck2 daemon for a fresh start
+  buck2 killall || true
 }
 
 function write_sccache_stub() {