diff --git a/code/portal_data.js b/code/portal_data.js
index 762a6df6..104fb2e5 100644
--- a/code/portal_data.js
+++ b/code/portal_data.js
@@ -93,6 +93,7 @@ window.findPortalLatLng = function(guid) {
 
 (function() {
   var cache = {};
+  var cache_level = 0;
   var GC_LIMIT = 5000; // run garbage collector when cache has more that 5000 items
   var GC_KEEP  = 4000; // keep the 4000 most recent items
 
@@ -128,13 +129,15 @@ window.findPortalLatLng = function(guid) {
 
   window.pushPortalGuidPositionCache = function(guid, latE6, lngE6) {
     cache[latE6+","+lngE6] = [guid, Date.now()];
+    cache_level += 1;
 
-    if(Object.keys(cache).length > GC_LIMIT) {
+    if(cache_level > GC_LIMIT) {
       Object.keys(cache) // get all latlngs
         .map(function(latlng) { return [latlng, cache[latlng][1]]; })  // map them to [latlng, timestamp]
         .sort(function(a,b) { return b[1] - a[1]; }) // sort them
         .slice(GC_KEEP) // drop the MRU
         .forEach(function(item) { delete cache[item[0]] }); // delete the rest
+      cache_level = Object.keys(cache).length
     }
   }
 })();