diff --git a/src/channel.c b/src/channel.c
index b013a85..7c649b1 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -1048,7 +1048,7 @@
 # if defined(UNIX)
 	/* Do not end the job when all output channels are closed, wait until
 	 * the job ended. */
-	if (isatty(in))
+	if (mch_isatty(in))
 	    channel->ch_to_be_closed |= (1U << PART_IN);
 # endif
     }