diff --git a/modules/ext.math.css b/modules/ext.math.css
index 36e3452..634f4b9 100644
--- a/modules/ext.math.css
+++ b/modules/ext.math.css
@@ -38,26 +38,6 @@ generated by Mathoid. See https://gerrit.wikimedia.org/r/#/c/166213/ */
 .mwe-math-fallback-source-inline { display: inline; vertical-align: middle; }
 .mwe-math-fallback-source-display { display: block; margin-left: auto; margin-right: auto; }
 
-/**
- * Browser-specific hacks are bad but let's use that for now...
- * See http://browserhacks.com/
- */
-@-moz-document url-prefix() {
-	/* For Gecko browsers, hide the SVG fallback and show the MathML instead.
-	 * We override the style for SVG and MathML above
-	 */
-	.mwe-math-mathml-a11y {
-		clip: auto;
-		overflow: visible;
-		position: static;
-		width: auto;
-		height: auto;
-		opacity: 1;
-	}
-	.mwe-math-mathml-inline + .mwe-math-fallback-image-inline,
-	.mwe-math-mathml-display + .mwe-math-fallback-image-display { display: none !important; }
-}
-
 /* PNG related styles from core */
 img.tex {
 	vertical-align: middle;