diff --git a/nb-convert.sh b/nb-convert.sh
index 9d92f38..e6da4ef 100755
--- a/nb-convert.sh
+++ b/nb-convert.sh
@@ -4,5 +4,5 @@ set -e
 
 jupyter nbconvert --TagRemovePreprocessor.enabled=True --TagRemovePreprocessor.remove_cell_tags no-convert --to script docs/examples/*.ipynb &&
 for file in docs/examples/*.txt;
-do mv -- $file ${file%.txt}.py;
+do mv -- "$file" "${file%.txt}.py";
 done