diff --git a/actions/aws-auth/resolve-aws-region.sh b/actions/aws-auth/resolve-aws-region.sh
index 85e80119f..9ff78f403 100644
--- a/actions/aws-auth/resolve-aws-region.sh
+++ b/actions/aws-auth/resolve-aws-region.sh
@@ -3,21 +3,23 @@
 # https://github.com/catnekaise/cognito-idpool-auth/blob/83ae9e159de469b3acd87ecb361d6b5957ee35ae/action.yml#L192-L227
 value=""
 
-if [ ! -z "${AWS_REGION}" ] && [ ! -z "${AWS_DEFAULT_REGION}" ]; then
+if [ -n "${AWS_REGION}" ] && [ -n "${AWS_DEFAULT_REGION}" ]; then
   value="$AWS_REGION"
 fi
 
-if [ -z "$value" ]; then
-  echo "Unable to resolve what AWS Region to use"
+readonly value
+
+if [ -z "${value}" ]; then
+  echo 'Unable to resolve what AWS region to use'
   exit 1
 fi
 
 # Some-effort validation of aws region
-if echo "$value" | grep -Eqv "^[a-z]{2}-[a-z]{4,9}-[0-9]$"; then
-  echo "Resolved value for AWS Region is invalid"
+if echo "${value}" | grep -Eqv '^[a-z]{2}-[a-z]{4,9}-[0-9]$'; then
+  echo 'Resolved value for AWS region is invalid'
   exit 1
 fi
 
-echo "value=$value" >> "$GITHUB_OUTPUT"
-echo "AWS_REGION=${AWS_REGION}" >> "$GITHUB_ENV"
-echo "AWS_DEFAULT_REGION=${AWS_DEFAULT_REGION}" >> "$GITHUB_ENV"
+echo "value=${value}" >> "${GITHUB_OUTPUT}"
+echo "AWS_REGION=${AWS_REGION}" >> "${GITHUB_ENV}"
+echo "AWS_DEFAULT_REGION=${AWS_DEFAULT_REGION}" >> "${GITHUB_ENV}"