diff --git a/src/parser.y b/src/parser.y
index d9acc10..15ce61c 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -11,6 +11,7 @@
 #include <arpa/inet.h>
 #include "bandwidthd.h"
 
+extern int yylex (void);
 extern unsigned int SubnetCount;
 extern struct SubnetData SubnetTable[];
 extern struct config config;