diff --git a/kernel/kls_pict/fmt_codec_pnm.cpp b/kernel/kls_pict/fmt_codec_pnm.cpp
index 184acfe..f7c94b4 100644
--- a/kernel/kls_pict/fmt_codec_pnm.cpp
+++ b/kernel/kls_pict/fmt_codec_pnm.cpp
@@ -22,6 +22,7 @@
 #include <iostream>
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 
 // we will use fork()
 #if defined CODEC_DJVU  \