--- a/layout/reftests/text-overflow/reftest.list
+++ b/layout/reftests/text-overflow/reftest.list
@@ -7,17 +7,17 @@ HTTP(..) == scroll-rounding.html scroll-
 HTTP(..) == anonymous-block.html anonymous-block-ref.html
 HTTP(..) == false-marker-overlap.html false-marker-overlap-ref.html
 HTTP(..) == visibility-hidden.html visibility-hidden-ref.html
 HTTP(..) == block-padding.html block-padding-ref.html
 HTTP(..) == quirks-decorations.html quirks-decorations-ref.html
 HTTP(..) == quirks-line-height.html quirks-line-height-ref.html
 HTTP(..) == standards-decorations.html standards-decorations-ref.html
 HTTP(..) == standards-line-height.html standards-line-height-ref.html
-HTTP(..) == selection.html selection-ref.html
+random-if(/^Windows\x20NT\x205\.1/.test(http.oscpu)) HTTP(..) == selection.html selection-ref.html # bug 668849
 HTTP(..) == marker-shadow.html marker-shadow-ref.html
 == aligned-baseline.html aligned-baseline-ref.html
 skip-if(Android) == clipped-elements.html clipped-elements-ref.html
 HTTP(..) == theme-overflow.html theme-overflow-ref.html
 HTTP(..) == table-cell.html table-cell-ref.html
 HTTP(..) == two-value-syntax.html two-value-syntax-ref.html
 HTTP(..) == single-value.html single-value-ref.html 
 HTTP(..) == atomic-under-marker.html atomic-under-marker-ref.html