diff --git a/contrib/ipfilter/lib/printipfexpr.c b/contrib/ipfilter/lib/printipfexpr.c
index 64c2f1c1a7e8..06b987e07575 100644
--- a/contrib/ipfilter/lib/printipfexpr.c
+++ b/contrib/ipfilter/lib/printipfexpr.c
@@ -3,7 +3,9 @@
 static void printport __P((int *));
 static void printhosts __P((int *));
 static void printsingle __P((int *));
+#ifdef USE_INET6
 static void printhostsv6 __P((int *));
+#endif
 
 void
 printipfexpr(array)