--- a/toolkit/modules/FinderHighlighter.jsm
+++ b/toolkit/modules/FinderHighlighter.jsm
@@ -36,17 +36,16 @@ const kRGBRE = /^rgba?\s*\(\s*(\d+)\s*,\
 // with, since the stylesheet for modal highlighting is inserted as an agent-sheet
 // in the active HTML document.
 const kModalIdPrefix = "cedee4d0-74c5-4f2d-ab43-4d37c0f9d463";
 const kModalOutlineId = kModalIdPrefix + "-findbar-modalHighlight-outline";
 const kModalStyle = `
 .findbar-modalHighlight-outline {
   position: absolute;
   background: #ffc535;
-  border-radius: 3px;
   box-shadow: 0 2px 0 0 rgba(0,0,0,.1);
   color: #000;
   display: -moz-box;
   margin: -2px 0 0 -2px !important;
   padding: 2px !important;
   pointer-events: none;
   z-index: 2;
 }
@@ -110,16 +109,21 @@ const kModalStyle = `
   background: #fff;
   margin: -1px 0 0 -1px !important;
   padding: 0 1px 2px 1px !important;
   position: absolute;
 }
 
 .findbar-modalHighlight-outlineMask[brighttext] > .findbar-modalHighlight-rect {
   background: #000;
+}
+
+.findbar-modalHighlight-outline,
+.findbar-modalHighlight-rect {
+  border-radius: 3px;
 }`;
 
 function mockAnonymousContentNode(domNode) {
   return {
     setTextContentForElement(id, text) {
       (domNode.querySelector("#" + id) || domNode).textContent = text;
     },
     getAttributeForElement(id, attrName) {