diff --git a/src/httpd.js.c b/src/httpd.js.c
index f26293cb..72a9d418 100644
--- a/src/httpd.js.c
+++ b/src/httpd.js.c
@@ -8,6 +8,8 @@
 
 #include "picohttpparser.h"
 
+#include <stdlib.h>
+
 #if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(_WIN32)
 #include <alloca.h>
 #endif