diff --git a/src/os_unix.c b/src/os_unix.c
index b0e0f02..150bdad 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -4168,7 +4168,6 @@
 # ifdef FEAT_GUI
 		if (pty_master_fd >= 0)
 		{
-		    close(pty_slave_fd);	/* close slave side of pty */
 		    fromshell_fd = pty_master_fd;
 		    toshell_fd = dup(pty_master_fd);
 		}
@@ -4637,6 +4636,14 @@
 		    break;
 	    }
 
+# ifdef FEAT_GUI
+	    /* Close slave side of pty.  Only do this after the child has
+	     * exited, otherwise the child may hang when it tries to write on
+	     * the pty. */
+	    if (pty_master_fd >= 0)
+		close(pty_slave_fd);
+# endif
+
 	    /* Make sure the child that writes to the external program is
 	     * dead. */
 	    if (wpid > 0)