diff --git a/lib/carto/tree/filterset.js b/lib/carto/tree/filterset.js
index 2866959..4fa569f 100644
--- a/lib/carto/tree/filterset.js
+++ b/lib/carto/tree/filterset.js
@@ -93,9 +93,9 @@ tree.Filterset.prototype.toJS = function(env) {
     }
     var attrs = "data";
     if (op === '=~') {
-      return "(" + attrs + "['" + filter.key.value  + "'] + '').match(" + (val.is === 'string' ? "'" + val.toString().replace(/'/g, "\\'") + "'" : val) + ")";
+      return "(" + attrs + "['" + filter.key.value  + "'] + '').match(" + (val.is === 'string' ? "'" + val.toString().replace(/'/g, "\\'").replace(/&/g, '&') + "'" : val) + ")";
     }
-    return attrs + "['" + filter.key.value  + "'] " + op + " " + (val.is === 'string' ? "'" + val.toString().replace(/'/g, "\\'") + "'" : val);
+    return attrs + "['" + filter.key.value  + "'] " + op + " " + (val.is === 'string' ? "'" + val.toString().replace(/'/g, "\\'").replace(/&/g, '&') + "'" : val);
   }).join(' && ');
 };