diff --git a/src/os_unix.c b/src/os_unix.c
index 5e744b6..ff76618 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -4150,6 +4150,11 @@
 #endif
 
 #if defined(FEAT_GUI) || defined(FEAT_JOB_CHANNEL)
+/*
+ * Open a PTY, with FD for the master and slave side.
+ * When failing "pty_master_fd" and "pty_slave_fd" are -1.
+ * When successful both file descriptors are stored.
+ */
     static void
 open_pty(int *pty_master_fd, int *pty_slave_fd)
 {
@@ -5380,6 +5385,17 @@
 		     ? INVALID_FD : fd_err[0] < 0 ? pty_master_fd : fd_err[0]);
 	channel_set_job(channel, job, options);
     }
+    else
+    {
+	if (fd_in[1] >= 0)
+	    close(fd_in[1]);
+	if (fd_out[0] >= 0)
+	    close(fd_out[0]);
+	if (fd_err[0] >= 0)
+	    close(fd_err[0]);
+	if (pty_master_fd >= 0)
+	    close(pty_master_fd);
+    }
 
     /* success! */
     return;