diff --git a/src/commands/Command.cpp b/src/commands/Command.cpp
index b0d0e812b..1b341586d 100644
--- a/src/commands/Command.cpp
+++ b/src/commands/Command.cpp
@@ -29,6 +29,7 @@
 
 #include <iostream>
 #include <vector>
+#include <stdlib.h>
 #include <Expression.h>
 #include <Att.h>
 #include <Timer.h>