diff -x '*~' -purN a/checkpeerlocal.c b/checkpeerlocal.c
--- a/checkpeerlocal.c	2015-08-25 00:03:26.000000000 +0200
+++ b/checkpeerlocal.c	2017-07-14 20:12:26.109653383 +0200
@@ -208,6 +208,7 @@ int checkpeerlocal(int sock)
     }
 #endif
 
+#ifdef HAVE_IPV6
     if (IN6_IS_ADDR_V4MAPPED(&addr.sin6.sin6_addr)) {
 	    /* map to IPv4 */
 	    struct sockaddr_in si;
@@ -216,6 +217,7 @@ int checkpeerlocal(int sock)
 	    memcpy(&addr.sin, &si, sizeof(struct sockaddr_in));
 	    D(pat(&addr.sa));
     }
+#endif
 
     if (getifaddrs(&ifap) != 0) {
 	D(printf("getifaddrs failed: %s\n", strerror(errno)));