--- a/browser/base/content/test/general/browser.ini
+++ b/browser/base/content/test/general/browser.ini
@@ -387,16 +387,17 @@ skip-if = e10s && debug && os == "win" #
 [browser_save_video.js]
 [browser_save_video_frame.js]
 [browser_scope.js]
 [browser_contentSearchUI.js]
 support-files =
   contentSearchUI.html
   contentSearchUI.js
 [browser_selectpopup.js]
+skip-if = (os == "linux" && debug) # Bug 1329991 - test fails intermittently on Linux debug builds
 [browser_selectTabAtIndex.js]
 [browser_ssl_error_reports.js]
 [browser_star_hsts.js]
 [browser_subframe_favicons_not_used.js]
 [browser_syncui.js]
 skip-if = os == 'linux' # Bug 1304272
 [browser_tab_close_dependent_window.js]
 [browser_tabDrop.js]