diff --git a/apps/files/css/detailsView.scss b/apps/files/css/detailsView.scss
index 46c177d63d..c292a45b96 100644
--- a/apps/files/css/detailsView.scss
+++ b/apps/files/css/detailsView.scss
@@ -122,7 +122,6 @@
 	top: 0;
 	right: 0;
 	padding: 15px;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
 	opacity: .5;
 	z-index: 1;
 }
diff --git a/apps/files/css/files.scss b/apps/files/css/files.scss
index 13746db9fc..8d5d245a6c 100644
--- a/apps/files/css/files.scss
+++ b/apps/files/css/files.scss
@@ -153,8 +153,6 @@ span.conflict-path, span.extension, span.uploading, td.date {
 	color: #999;
 }
 span.conflict-path, span.extension {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=70)";
-	filter: alpha(opacity=70);
 	opacity: .7;
 	-webkit-transition: opacity 300ms;
 	-moz-transition: opacity 300ms;
@@ -166,8 +164,6 @@ tr:hover span.conflict-path,
 tr:focus span.conflict-path,
 tr:hover span.extension,
 tr:focus span.extension {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
-	filter: alpha(opacity=100);
 	opacity: 1;
 	color: #777;
 }
@@ -198,8 +194,6 @@ table th .sort-indicator {
 	margin-left: 5px;
 	display: inline-block;
 	vertical-align: text-bottom;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=30)";
-	filter: alpha(opacity=30);
 	opacity: .3;
 }
 .sort-indicator.hidden,
@@ -434,8 +428,6 @@ table td.filename .uploadtext {
 	height: 20px;
 	padding: 10px 0;
 	font-size: 11px;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
-	filter: alpha(opacity=50);
 	opacity: .5;
 }
 
@@ -531,8 +523,6 @@ table td.filename .uploadtext {
 
 /* force show the loading icon, not only on hover */
 #fileList .icon-loading-small {
-	-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
-	filter:alpha(opacity=100);
 	opacity: 1 !important;
 	display: inline !important;
 }
@@ -575,8 +565,6 @@ a.action > img {
 	display: inline;
 	padding: 17px 8px;
 	line-height: 50px;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
-	filter: alpha(opacity=0);
 	opacity: 0;
 }
 #fileList a.action.action-share {
@@ -597,8 +585,6 @@ a.action > img {
 #fileList a.action.disabled:hover,
 #fileList a.action.disabled:focus,
 #fileList a.action.disabled img {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=30)";
-	filter: alpha(opacity=30);
 	opacity: .3;
 }
 
@@ -610,8 +596,6 @@ a.action > img {
 #fileList .fileActionsMenu a.action,
 /* show share action of shared items darker to distinguish from non-shared */
 #fileList a.action.action-share.shared-style {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=70)";
-	filter: alpha(opacity=70);
 	opacity: .7;
 }
 
@@ -626,8 +610,6 @@ a.action > img {
 }
 
 #fileList .action.action-favorite.permanent {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
-	filter: alpha(opacity=100);
 	opacity: 1;
 }
 
@@ -636,8 +618,6 @@ a.action > img {
 /* show share action of shared items darker to distinguish from non-shared */
 #fileList a.action.action-share.shared-style:hover,
 #fileList a.action.action-share.shared-style:focus {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
-	filter: alpha(opacity=100);
 	opacity: 1;
 }
 
@@ -655,8 +635,6 @@ a.action > img {
 }
 
 .summary {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=30)";
-	filter: alpha(opacity=30);
 	opacity: .3;
 	/* add whitespace to bottom of files list to correctly show dropdowns */
 	height: 300px;
@@ -701,7 +679,6 @@ table.dragshadow td.size {
 	background-repeat: no-repeat no-repeat;
 	background-position: 50%;
 	opacity: 0.7;
-	filter: alpha(opacity=70);
 	transition: opacity 100ms;
 	-moz-transition: opacity 100ms;
 	-o-transition: opacity 100ms;
diff --git a/apps/files/css/mobile.scss b/apps/files/css/mobile.scss
index 9e1c8a01d8..eefc92c816 100644
--- a/apps/files/css/mobile.scss
+++ b/apps/files/css/mobile.scss
@@ -51,11 +51,9 @@ table td.filename .nametext {
 	display: none !important;
 }
 #fileList a.action.action-favorite {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=70)" !important;
 	opacity: .7 !important;
 }
 #fileList a.action.action-favorite {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=30)" !important;
 	opacity: .3 !important;
 }
 
diff --git a/apps/files_sharing/css/public.scss b/apps/files_sharing/css/public.scss
index 6d9fcf14ef..652d36f77d 100644
--- a/apps/files_sharing/css/public.scss
+++ b/apps/files_sharing/css/public.scss
@@ -97,8 +97,6 @@ thead {
 
 .directLink label {
 	font-weight: normal;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
-	filter: alpha(opacity=50);
 	opacity: .5;
 }
 .directLink input {
diff --git a/apps/files_versions/css/versions.css b/apps/files_versions/css/versions.css
index cd63a90ab5..74ab146b05 100644
--- a/apps/files_versions/css/versions.css
+++ b/apps/files_versions/css/versions.css
@@ -16,8 +16,6 @@
 .versionsTabView a,
 .versionsTabView div > span {
 	vertical-align: middle;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
-	filter: alpha(opacity=50);
 	opacity: .5;
 }
 
@@ -27,8 +25,6 @@
 
 .versionsTabView a:hover,
 .versionsTabView a:focus {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=100)";
-	filter: alpha(opacity=100);
 	opacity: 1;
 }
 
diff --git a/core/css/apps.scss b/core/css/apps.scss
index 5f90f13e93..fb0eb7e43e 100644
--- a/core/css/apps.scss
+++ b/core/css/apps.scss
@@ -34,7 +34,6 @@ h3 {
 /* do not use italic typeface style, instead lighter color */
 em {
 	font-style: normal;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=50)';
 	opacity: .5;
 }
 
@@ -820,12 +819,8 @@ kbd {
 			box-shadow: none;
 			width: 100%;
 			/* Override the app-navigation li opacity */
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)' !important;
-			filter: alpha(opacity = 70) !important;
 			opacity: .7 !important;
 			&:hover, &:focus, &.active {
-				-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)' !important;
-				filter: alpha(opacity = 100) !important;
 				opacity: 1 !important;
 			}
 			/* prevent .action class to break the design */
diff --git a/core/css/guest.css b/core/css/guest.css
index 1081b95fb3..dacf79b37b 100644
--- a/core/css/guest.css
+++ b/core/css/guest.css
@@ -43,7 +43,6 @@ p.info a:hover {
 }
 em {
 	font-style: normal;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=50)';
 	opacity: .5;
 }
 
@@ -309,7 +308,6 @@ label.infield {
 	padding: 14px !important;
 }
 #show:checked + label, #dbpassword-toggle:checked + label, #personal-show:checked + label {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=80)';
 	opacity: .8;
 }
 #show + label, #dbpassword-toggle + label, #personal-show + label {
@@ -319,7 +317,6 @@ label.infield {
 	background-image: url('../img/actions/toggle.svg?v=1');
 	background-repeat: no-repeat;
 	background-position: center;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=30)';
 	opacity: .3;
 }
 #show + label:before, #dbpassword-toggle + label:before, #personal-show + label:before {
@@ -520,7 +517,6 @@ form #selectDbType label.ui-state-active {
 .error a {
 	color: #fff !important;
 	font-weight: 600 !important;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 	opacity: 1;
 }
 .error a.button {
diff --git a/core/css/header.scss b/core/css/header.scss
index fae11a878e..e9edfe0bfb 100644
--- a/core/css/header.scss
+++ b/core/css/header.scss
@@ -86,14 +86,11 @@
 	height: 45px;
 	/* header height */
 	box-sizing: border-box;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 	opacity: 1;
 	&:focus {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=75)';
 		opacity: .75;
 	}
 	&:hover, &:active {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 		opacity: 1;
 	}
 }
@@ -156,30 +153,25 @@
 /* hover effect for app switcher label */
 
 .header-appname-container .header-appname {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=75)';
 	opacity: .75;
 }
 
 .menutoggle {
 	.icon-caret {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=75)';
 		opacity: .75;
 	}
 	&:hover {
 		.header-appname, .icon-caret {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
 	&:focus {
 		.header-appname, .icon-caret {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
 	&.active {
 		.header-appname, .icon-caret {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
@@ -276,7 +268,6 @@ nav {
 		}
 		svg,
 		span {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)';
 			opacity: .7;
 		}
 		svg {
@@ -286,12 +277,10 @@ nav {
 		&:focus svg,
 		&:hover span,
 		&:focus span {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 		&.active {
 			svg, span {
-				-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 				opacity: 1;
 			}
 		}
@@ -315,7 +304,6 @@ nav {
 		height: 16px;
 	}
 	.app-icon {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=0)';
 		opacity: 0;
 	}
 }
@@ -356,7 +344,6 @@ nav {
 		cursor: pointer;
 	}
 	img {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)';
 		opacity: .7;
 		margin-bottom: -2px;
 	}
@@ -366,7 +353,6 @@ nav {
 		color: $color-primary-text;
 		img,
 		#expandDisplayName {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
@@ -428,7 +414,6 @@ nav {
 		color: $color-main-text;
 		padding: 10px 12px 0;
 		box-sizing: border-box;
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)';
 		opacity: .7;
 		img {
 			margin-bottom: -3px;
@@ -438,7 +423,6 @@ nav {
 		&:focus,
 		&:active,
 		&.active {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
diff --git a/core/css/styles.scss b/core/css/styles.scss
index ad75c0c2fc..be0b200ce3 100644
--- a/core/css/styles.scss
+++ b/core/css/styles.scss
@@ -187,7 +187,6 @@ body {
 		cursor: pointer;
 		-webkit-transition: all 100ms;
 		transition: all 100ms;
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)';
 		opacity: .6;
 		&:focus, &:active, &:valid {
 			color: $color-primary-text;
@@ -197,7 +196,6 @@ body {
 			border: 1px solid rgba($color-primary-text, 0.5) !important;
 		}
 		&:hover, &:focus, &:active {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 		& ~ .icon-close-white {
@@ -327,7 +325,6 @@ body {
 	height: 64px;
 	width: 64px;
 	margin: 0 auto 15px;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=40)';
 	opacity: .4;
 }
 
@@ -580,7 +577,6 @@ label.infield {
 }
 
 #show:checked + label, #dbpassword:checked + label, #personal-show:checked + label {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=80)';
 	opacity: .8;
 }
 
@@ -591,7 +587,6 @@ label.infield {
 	background-image: url('../img/actions/toggle.svg?v=1');
 	background-repeat: no-repeat;
 	background-position: center;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=30)';
 	opacity: .3;
 }
 
@@ -723,7 +718,6 @@ label.infield {
 	.warning {
 		margin: 0 7px 5px 4px;
 		legend {
-			-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 			opacity: 1;
 		}
 	}
@@ -856,7 +850,6 @@ td.avatar {
 	top: 0;
 	border-bottom-left-radius: 3px;
 	border-bottom-right-radius: 3px;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=90)';
 	opacity: .9;
 	span {
 		cursor: pointer;
@@ -882,19 +875,16 @@ td.avatar {
 }
 
 tr .action:not(.permanent), .selectedActions a {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=0)';
 	opacity: 0;
 }
 
 tr {
 	&:hover .action, &:focus .action, .action.permanent {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=50)';
 		opacity: .5;
 	}
 }
 
 .selectedActions a {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=50)';
 	opacity: .5;
 }
 
@@ -904,27 +894,23 @@ tr .action {
 }
 
 .header-action {
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=80)';
 	opacity: .8;
 }
 
 tr {
 	&:hover .action:hover, &:focus .action:focus {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 		opacity: 1;
 	}
 }
 
 .selectedActions a {
 	&:hover, &:focus {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 		opacity: 1;
 	}
 }
 
 .header-action {
 	&:hover, &:focus {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=100)';
 		opacity: 1;
 	}
 }
@@ -1359,7 +1345,6 @@ div.crumb {
 		top: 8px !important;
 	}
 	&:hover, &:focus, a:focus, &:active {
-		-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=70)';
 		opacity: .7;
 	}
 }
@@ -1422,5 +1407,4 @@ fieldset {
 	width: 0;
 	height: 0;
 	opacity: 0;
-	-ms-filter: 'progid:DXImageTransform.Microsoft.Alpha(Opacity=0)';
 }
diff --git a/core/css/tooltip.scss b/core/css/tooltip.scss
index 7c6a2f8a58..dad7b95bbd 100644
--- a/core/css/tooltip.scss
+++ b/core/css/tooltip.scss
@@ -31,10 +31,8 @@
 	font-size: 12px;
 	opacity: 0;
 	z-index: 100000;
-	filter: alpha(opacity = 0);
 	&.in {
 		opacity: 1;
-		filter: alpha(opacity = 100);
 	}
 
 	&.top {
diff --git a/core/search/css/results.css b/core/search/css/results.css
index e55c2926fd..2e3791a47f 100644
--- a/core/search/css/results.css
+++ b/core/search/css/results.css
@@ -88,8 +88,6 @@
 	color: #545454;
 }
 #searchresults .path {
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
-	filter: alpha(opacity=50);
 	opacity: .5;
 }
 #searchresults .text em {
diff --git a/settings/css/settings.scss b/settings/css/settings.scss
index 5f9b7d6a4c..2ec7f57532 100644
--- a/settings/css/settings.scss
+++ b/settings/css/settings.scss
@@ -884,7 +884,6 @@ span.version {
 	clear: both;
 	padding: 7px 0;
 	cursor: pointer;
-	-ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=50)";
 	opacity: .5;
 }