diff --git a/liba52/compare.c b/liba52/compare.c
index 99ebbdde15..d5bade9eb7 100644
--- a/liba52/compare.c
+++ b/liba52/compare.c
@@ -3,6 +3,7 @@
 // and dies if there is too large an error ( ABS(a-b)>1 ).
 
 #include <stdio.h>
+#include <stdlib.h>
 
 // FIXME: No checks but it is just for debugging so who cares ;)