diff --git a/src/engine/gnc-commodity.c b/src/engine/gnc-commodity.c
index a14ea91c02..a0feb4d9de 100644
--- a/src/engine/gnc-commodity.c
+++ b/src/engine/gnc-commodity.c
@@ -30,6 +30,7 @@
 #include <limits.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <glib.h>
 #include <regex.h>