diff --git a/src/nvim/testdir/test_quotestar.vim b/src/nvim/testdir/test_quotestar.vim
index ce5a9ee827..77a5153a81 100644
--- a/src/nvim/testdir/test_quotestar.vim
+++ b/src/nvim/testdir/test_quotestar.vim
@@ -108,7 +108,8 @@ func Do_test_quotestar_for_x11()
       call remote_send(name, ":gui -f\<CR>")
     endif
     " Wait for the server in the GUI to be up and answering requests.
-    call WaitForAssert({-> assert_match("1", remote_expr(name, "has('gui_running')", "", 1))})
+    " On some systems and with valgrind this can be very slow.
+    call WaitForAssert({-> assert_match("1", remote_expr(name, "has('gui_running')", "", 1))}, 10000)
 
     call remote_send(name, ":let @* = 'maybe'\<CR>")
     call WaitForAssert({-> assert_equal("maybe", remote_expr(name, "@*", "", 2))})