diff --git a/src/cc-compat.h b/src/cc-compat.h
index 37f1ea81e..e73cb6de8 100644
--- a/src/cc-compat.h
+++ b/src/cc-compat.h
@@ -7,6 +7,8 @@
 #ifndef INCLUDE_compat_h__
 #define INCLUDE_compat_h__
 
+#include <stdarg.h>
+
 /*
  * See if our compiler is known to support flexible array members.
  */