diff --git a/.github/scripts/rename/copyright.sh b/.github/scripts/rename/copyright.sh
index 12b1848f09..c0f64de496 100755
--- a/.github/scripts/rename/copyright.sh
+++ b/.github/scripts/rename/copyright.sh
@@ -5,7 +5,7 @@ set -e
 
 # On MacOS, ensure that GNU sed is installed and available as `gsed`.
 SED_COMMAND=sed
-if [[ "$OSTYPE" == "darwin"* ]]; then
+if [[ "${OSTYPE}" == 'darwin'* ]]; then
   if ! command -v gsed &> /dev/null; then
       echo "Error: gsed is not installed. Please install it using 'brew install gnu-sed'."
       exit 1