diff --git a/src/libpostal.c b/src/libpostal.c
index 85e8a332..ca04cfe5 100644
--- a/src/libpostal.c
+++ b/src/libpostal.c
@@ -1,5 +1,8 @@
+#include <stdlib.h>
+
 #include "libpostal.h"
 
+#include "klib/khash.h"
 #include "klib/ksort.h"
 #include "log/log.h"