diff --git a/dev/release/post-01-tag.sh b/dev/release/post-01-tag.sh
index df0f6756c0e7c..2fa48f1230219 100755
--- a/dev/release/post-01-tag.sh
+++ b/dev/release/post-01-tag.sh
@@ -17,7 +17,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-set -e
+set -eu
 set -o pipefail
 
 if [ "$#" -ne 2 ]; then
@@ -25,8 +25,11 @@ if [ "$#" -ne 2 ]; then
   exit
 fi
 
+version=$1
+rc=$2
+
 # Create the release tag and trigger the Publish Release workflow.
-release_candidate_tag=apache-arrow-${version}-rc${num}
 release_tag=apache-arrow-${version}
-git tag -a ${release_tag} ${release_candidate_tag}^{} -m "[Release] Apache Arrow Release ${version}"
+release_candidate_tag=${release_tag}-rc${rc}
+git tag -a ${release_tag} ${release_candidate_tag} -m "[Release] Apache Arrow Release ${version}"
 git push apache ${release_tag}