diff --git a/src/testdir/test_selectmode.vim b/src/testdir/test_selectmode.vim
index 3adb843..3296f7e 100644
--- a/src/testdir/test_selectmode.vim
+++ b/src/testdir/test_selectmode.vim
@@ -165,7 +165,10 @@
   let save_term = &term
   let save_ttymouse = &ttymouse
   call test_override('no_query_mouse', 1)
-  set mouse=a term=xterm mousetime=200
+
+  " 'mousetime' must be sufficiently large, or else the test is flaky when
+  " using a ssh connection with X forwarding; i.e. ssh -X.
+  set mouse=a term=xterm mousetime=1000
   set selectmode=mouse
   new