--- a/src/java.base/share/native/libnet/net_util.c	Fri Mar 02 19:10:12 2018 +0100
+++ b/src/java.base/share/native/libnet/net_util.c	Sat Mar 03 08:21:47 2018 +0100
@@ -33,12 +33,12 @@
 static int IPv6_available;
 static int REUSEPORT_available;
 
-JNIEXPORT jint JNICALL ipv6_available()
+JNIEXPORT jint JNICALL ipv6_available(void)
 {
     return IPv6_available;
 }
 
-JNIEXPORT jint JNICALL reuseport_available()
+JNIEXPORT jint JNICALL reuseport_available(void)
 {
     return REUSEPORT_available;
 }