diff --git a/src/sysutils.cpp b/src/sysutils.cpp
index 332723c..1e6ef3a 100644
--- a/src/sysutils.cpp
+++ b/src/sysutils.cpp
@@ -25,6 +25,7 @@
 #endif /* !__APPLE__, !_WIN32 */
 #endif /* !_WIN32 */
 
+#include <cstdlib>
 #include <iostream>