diff --git a/src/iperf_api.h b/src/iperf_api.h
index bc68b96..7491551 100644
--- a/src/iperf_api.h
+++ b/src/iperf_api.h
@@ -283,6 +283,7 @@ enum {
     IEDAEMON = 133,	    // Unable to become a daemon process
     IESETCONGESTION = 134,  // Unable to set TCP_CONGESTION
     IEPIDFILE = 135,	    // Unable to write PID file
+    IEV6ONLY = 136,  	    // Unable to set/unset IPV6_V6ONLY (check perror)
     /* Stream errors */
     IECREATESTREAM = 200,   // Unable to create a new stream (check herror/perror)
     IEINITSTREAM = 201,     // Unable to initialize stream (check herror/perror)
diff --git a/src/iperf_error.c b/src/iperf_error.c
index 645df48..cbd0565 100644
--- a/src/iperf_error.c
+++ b/src/iperf_error.c
@@ -299,6 +299,10 @@ iperf_strerror(int i_errno)
             snprintf(errstr, len, "unable to write PID file");
             perr = 1;
             break;
+	case IEV6ONLY:
+	    snprintf(errstr, len, "Unable to set/reset IPV6_V6ONLY");
+	    perr = 1;
+	    break;
     }
 
     if (herr || perr)
diff --git a/src/iperf_tcp.c b/src/iperf_tcp.c
index 4c8fcb8..7d9ad02 100644
--- a/src/iperf_tcp.c
+++ b/src/iperf_tcp.c
@@ -208,7 +208,15 @@ iperf_tcp_listen(struct iperf_test *test)
 		opt = 0;
 	    else if (test->settings->domain == AF_INET6)
 		opt = 1;
-	    setsockopt(s, SOL_SOCKET, IPV6_V6ONLY, (char *) &opt, sizeof(opt));
+	    if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, 
+			   (char *) &opt, sizeof(opt)) < 0) {
+		saved_errno = errno;
+		close(s);
+		freeaddrinfo(res);
+		errno = saved_errno;
+		i_errno = IEV6ONLY;
+		return -1;
+	    }
 	}
 
         if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {