--- opendbx-1.3.10/test/odbxplus-regression.cpp
+++ opendbx-1.3.10/test/odbxplus-regression.cpp
@@ -12,6 +12,7 @@
 #include <vector>
 #include <iostream>
 #include <opendbx/api>
+#include <cstdlib>
 
 #ifdef HAVE_CONFIG_H
 #include <config.h>