diff --git a/postgres-dump-zstd-docker-sock.sh b/postgres-dump-zstd-docker-sock.sh
index edbec1f..697d716 100755
--- a/postgres-dump-zstd-docker-sock.sh
+++ b/postgres-dump-zstd-docker-sock.sh
@@ -121,7 +121,7 @@ if [ ! -S "$DOCKER_SOCKET" ]; then
 fi
 
 timestamp=$(date +%Y-%m-%d_%H-%M-%S)
-backup_path="$BACKUP_DIR/${BACKUP_PREFIX}${timestamp}.zst"
+backup_path="$BACKUP_DIR/${BACKUP_PREFIX}${timestamp}.sql.zst"
 docker_api_base="http://localhost/${DOCKER_API_VERSION}"
 exec_create_endpoint="${docker_api_base}/containers/${PG_CONTAINER_NAME}/exec"