diff --git a/files/css/files.css b/files/css/files.css
index 512e462cb6..9e950517b8 100644
--- a/files/css/files.css
+++ b/files/css/files.css
@@ -64,8 +64,8 @@ table td.filename .nametext { width:60%; }
 table td.filename form { float:left; font-size:.85em; }
 table thead.fixed tr{ position:fixed; top:6.5em; z-index:49; -moz-box-shadow:0 -3px 7px #ddd; -webkit-box-shadow:0 -3px 7px #ddd; box-shadow:0 -3px 7px #ddd; }
 table thead.fixed { height:2em; }
-#fileList tr td.filename>input[type=checkbox]:first-child { opacity:0; float:left; margin:.7em 0 0 1em; /* bigger clickable area doesn’t work in FF width:2.8em; height:2.4em;*/ -webkit-transition:opacity 500ms; -moz-transition:opacity 500ms; -o-transition:opacity 500ms; transition:opacity 500ms; }
-#fileList tr td.filename>input[type="checkbox"]:hover:first-child { opacity:.8; }
+#fileList tr td.filename>input[type=checkbox]:first-child { opacity:0; -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=0)"; float:left; margin:.7em 0 0 1em; /* bigger clickable area doesn’t work in FF width:2.8em; height:2.4em;*/ -webkit-transition:opacity 500ms; -moz-transition:opacity 500ms; -o-transition:opacity 500ms; transition:opacity 500ms; }
+#fileList tr td.filename>input[type="checkbox"]:hover:first-child { opacity:.8; -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=80)"; }
 #fileList tr td.filename>input[type="checkbox"]:checked:first-child { opacity:1; }
 #fileList tr td.filename { -webkit-transition:background-image 500ms; -moz-transition:background-image 500ms; -o-transition:background-image 500ms; transition:background-image 500ms; }
 #select_all { float:left; margin:.3em 0.6em 0 .5em; }