diff --git a/include/mosquitto/libcommon_file.h b/include/mosquitto/libcommon_file.h
index 6c0a0f61..0b03648e 100644
--- a/include/mosquitto/libcommon_file.h
+++ b/include/mosquitto/libcommon_file.h
@@ -19,6 +19,7 @@ Contributors:
 #ifndef MOSQUITTO_LIBCOMMON_FILE_H
 #define MOSQUITTO_LIBCOMMON_FILE_H
 
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdio.h>