diff --git a/lib/ace/autocomplete/popup.js b/lib/ace/autocomplete/popup.js
index e1ec86c2..4cf29073 100644
--- a/lib/ace/autocomplete/popup.js
+++ b/lib/ace/autocomplete/popup.js
@@ -206,9 +206,12 @@ var AcePopup = function(parentNode) {
     };
     popup.show = function(pos, lineHeight) {
         var el = this.container;
-        if (pos.top > window.innerHeight / 2  + lineHeight) {
+        var screenHeight = window.innerHeight;
+        var renderer = this.renderer;
+        var maxH = renderer.$maxLines * lineHeight;
+        if (pos.top +maxH > screenHeight - lineHeight) {
             el.style.top = "";
-            el.style.bottom = window.innerHeight - pos.top + "px";
+            el.style.bottom = screenHeight - pos.top + "px";
         } else {
             pos.top += lineHeight;
             el.style.top = pos.top + "px";