diff --git a/lib/ace/test/mockrenderer.js b/lib/ace/test/mockrenderer.js
index 8d931483..9eb2b5c1 100644
--- a/lib/ace/test/mockrenderer.js
+++ b/lib/ace/test/mockrenderer.js
@@ -94,7 +94,17 @@ MockRenderer.prototype.updateCursor = function(position) {
     this.cursor.column = position.column;
 };
 
-MockRenderer.prototype.scrollToLine = function(row) {
+MockRenderer.prototype.scrollToLine = function(line, center) {
+    var lineHeight = { lineHeight: 16 };
+    var row = 0;
+    for (var l = 1; l < line; l++) {
+        row += this.session.getRowHeight(lineHeight, l-1) / lineHeight.lineHeight;
+    }
+
+    if (center) {
+        row -= this.visibleRowCount / 2;
+    }
+    this.scrollToRow(row);
 };
 
 MockRenderer.prototype.scrollCursorIntoView = function() {