diff --git a/.github/build-packages.php b/.github/build-packages.php
index b67a699609..83f4b4336c 100644
--- a/.github/build-packages.php
+++ b/.github/build-packages.php
@@ -14,7 +14,7 @@ $packages = array();
 $flags = \PHP_VERSION_ID >= 50400 ? JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE : 0;
 
 foreach ($dirs as $k => $dir) {
-    if (!system("git diff --name-only $mergeBase -- $dir", $exitStatus)) {
+    if (!system("git diff --name-only \"$mergeBase\" -- $dir", $exitStatus)) {
         if ($exitStatus) {
             exit($exitStatus);
         }