diff --git a/src/unix/newlib/mod.rs b/src/unix/newlib/mod.rs
index 0fd01f9acec47ac09374d4fc7f4584b5b91292fc..c9a25a35d41e5d148e430b73c0818caeb30b8b51 100644
--- a/src/unix/newlib/mod.rs
+++ b/src/unix/newlib/mod.rs
@@ -539,8 +539,8 @@ pub const IPV6_MULTICAST_IF: ::c_int = 9;
 pub const IPV6_MULTICAST_HOPS: ::c_int = 10;
 pub const IPV6_MULTICAST_LOOP: ::c_int = 11;
 pub const IPV6_V6ONLY: ::c_int = 27;
-pub const IPV6_JOIN_GROUP ::c_int = 12;
-pub const IPV6_LEAVE_GROUP ::c_int = 13;
+pub const IPV6_JOIN_GROUP: ::c_int = 12;
+pub const IPV6_LEAVE_GROUP: ::c_int = 13;
 pub const IPV6_ADD_MEMBERSHIP: ::c_int = 12;
 pub const IPV6_DROP_MEMBERSHIP: ::c_int = 13;