diff --git a/doctest.sh b/doctest.sh
index 6c0bdf0f..4035bde9 100755
--- a/doctest.sh
+++ b/doctest.sh
@@ -44,7 +44,7 @@ function generate_expected_output()
 }
 
 rm -rf tmp/doctest
-mkdir tmp/doctest
+mkdir -p tmp/doctest
 
 for file in "${files[@]}"; do
     echo "Extracting doctests from $file..."