diff --git a/src/channel.c b/src/channel.c
index f6ffcd6..41d19f5 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -2750,6 +2750,7 @@
     return TRUE;
 }
 
+#if defined(FEAT_NETBEANS_INTG) || defined(PROTO)
 /*
  * Return TRUE when channel "channel" is open for writing to.
  * Also returns FALSE or invalid "channel".
@@ -2760,6 +2761,7 @@
     return channel != NULL && (channel->CH_SOCK_FD != INVALID_FD
 			  || channel->CH_IN_FD != INVALID_FD);
 }
+#endif
 
 /*
  * Return TRUE when channel "channel" is open for reading or writing.