diff --git a/MathMathML.php b/MathMathML.php
index 40bc77c..d29210a 100644
--- a/MathMathML.php
+++ b/MathMathML.php
@@ -446,7 +446,7 @@ class MathMathML extends MathRenderer {
 		} else {
 			$element = 'span';
 		}
-		$attribs = [];
+		$attribs = [ 'class' => 'mwe-math-element' ];
 		if ( $this->getID() !== '' ) {
 			$attribs['id'] = $this->getID();
 		}
diff --git a/modules/ext.math.css b/modules/ext.math.css
index 69ea129..7ee2f9b 100644
--- a/modules/ext.math.css
+++ b/modules/ext.math.css
@@ -57,3 +57,8 @@ generated by Mathoid. See https://gerrit.wikimedia.org/r/#/c/166213/ */
 img.tex {
 	vertical-align: middle;
 }
+
+.mwe-math-element {
+	overflow-x: auto;
+	max-width: 100%;
+}