--- a/devtools/client/themes/boxmodel.css
+++ b/devtools/client/themes/boxmodel.css
@@ -117,16 +117,18 @@
   margin: 0;
   text-align: center;
 }
 
 #boxmodel-main > p > span,
 #boxmodel-main > p > input {
   vertical-align: middle;
   pointer-events: auto;
+  unicode-bidi: embed;
+  direction: ltr;
 }
 
 /* Coordinates for the region sizes */
 
 .boxmodel-top,
 .boxmodel-bottom {
   width: calc(100% - 2px);
   text-align: center;
@@ -245,14 +247,15 @@
 .boxmodel-size > span {
   cursor: default;
 }
 
 /* Box Model Info: contains the position and size of the element */
 
 #boxmodel-element-size {
   flex: 1;
+  direction: ltr;
 }
 
 #boxmodel-position-group {
   display: flex;
   align-items: center;
 }