Index: include/liquid.h
--- include/liquid.h.orig
+++ include/liquid.h
@@ -33,6 +33,7 @@ extern "C" {
 #include <inttypes.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <stdio.h>
 #include <time.h>
 
