diff --git a/scripts/wget-and-sci.sh b/scripts/wget-and-sci.sh
index 1b79fc3..5e7585e 100755
--- a/scripts/wget-and-sci.sh
+++ b/scripts/wget-and-sci.sh
@@ -1,13 +1,18 @@
 #!/bin/sh
 # NOTE: This script assumes that the url is a .tar.gz file.
-# TODO: check if $# is >= 1 and give a warning that the extract dir should be provided.
+if [ "$#" -lt 1 ]; then
+    printf '%s\n' "usage: $0 EXTRACT_DIR" >&2
+    printf '%s\n' "EXTRACT_DIR is the directory to enter after extracting the archive." >&2
+    exit 2
+fi
+
 set -ex  # print all that we're doing (no need for echo's)
 env
 tmpdir=$(mktemp -d)
 wget "$SCI_PIPELINE_URL" -P "$tmpdir"
 cd "$tmpdir"
 tar xf *.tar.gz
-cd $1
+cd "$1"
 sh .sci.sh
 cd -
 rm -rf "$tmpdir"