diff --git a/scad.sh b/scad.sh
index 448402c..aef2ee0 100644
--- a/scad.sh
+++ b/scad.sh
@@ -31,6 +31,9 @@ function getParts () {
 	echo "${tmpFile}"
 }
 
+mkdir -p stl
+mkdir -p img
+
 if [[ -z "${2}" ]]; then
 	echo "Generate all parts in ${SRC}..."
 	partsList=$(getParts)