diff --git a/lib/codemirror.js b/lib/codemirror.js
index 06042fe884..1bcc6b1cec 100644
--- a/lib/codemirror.js
+++ b/lib/codemirror.js
@@ -14,7 +14,6 @@ window.CodeMirror = (function() {
   var ie = /MSIE \d/.test(navigator.userAgent);
   var ie_lt8 = /MSIE [1-7]\b/.test(navigator.userAgent);
   var ie_lt9 = /MSIE [1-8]\b/.test(navigator.userAgent);
-  var quirksMode = ie && document.documentMode == 5;
   var webkit = /WebKit\//.test(navigator.userAgent);
   var chrome = /Chrome\//.test(navigator.userAgent);
   var opera = /Opera\//.test(navigator.userAgent);
@@ -582,13 +581,12 @@ window.CodeMirror = (function() {
     } else {
       headPos = cursorCoords(cm, selHead(cm.view), "div");
       var fragment = document.createDocumentFragment();
-      var clientWidth = display.lineSpace.clientWidth || display.lineSpace.offsetWidth;
-      var add = function(left, top, right, bottom) {
+      var clientWidth = display.lineSpace.clientWidth;
+      var add = function(left, top, width, bottom) {
         if (top < 0) top = 0;
-        var rstyle = quirksMode ? "width: " + (!right ? clientWidth : clientWidth - right - left) + "px"
-        : "right: " + right + "px";
         fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
-                                 "px; top: " + top + "px; " + rstyle + "; height: " + (bottom - top) + "px"));
+                                 "px; top: " + top + "px; width: " + (width == null ? clientWidth : width) +
+                                 "px; height: " + (bottom - top) + "px"));
       };
 
       var middleFrom = sel.from.line + 1, middleTo = sel.to.line - 1, sameLine = sel.from.line == sel.to.line;
@@ -601,13 +599,13 @@ window.CodeMirror = (function() {
           var rightPos = coords(dir == "rtl" ? from : to - 1);
           var left = leftPos.left, right = rightPos.right;
           if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
-            add(left, leftPos.top, 0, leftPos.bottom);
+            add(left, leftPos.top, null, leftPos.bottom);
             left = paddingLeft(display);
-            if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, 0, rightPos.top);
+            if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
           }
           if (toArg == null && to == lineLen) right = clientWidth;
           rVal = retTop ? Math.min(rightPos.top, rVal) : Math.max(rightPos.bottom, rVal);
-          add(left, rightPos.top, clientWidth - right, rightPos.bottom);
+          add(left, rightPos.top, right - left, rightPos.bottom);
         });
         return rVal;
       };
@@ -634,7 +632,7 @@ window.CodeMirror = (function() {
         middleTop = Math.min(middleTop, top.top);
         middleBot = Math.max(middleBot, bottom.bottom);
       }
-      if (middleTop < middleBot) add(paddingLeft(display), middleTop, 0, middleBot);
+      if (middleTop < middleBot) add(paddingLeft(display), middleTop, null, middleBot);
 
       removeChildrenAndAdd(display.selectionDiv, fragment);
       display.cursor.style.display = display.otherCursor.style.display = "none";