diff --git a/ippisite/ippidb/static/js/ippidb-query-url.js b/ippisite/ippidb/static/js/ippidb-query-url.js
index 8020e53793484ca0b0a6d604103f5a50c822c693..014fb0461d6fb4713c7370652b5f0452611b4be6 100644
--- a/ippisite/ippidb/static/js/ippidb-query-url.js
+++ b/ippisite/ippidb/static/js/ippidb-query-url.js
@@ -11,7 +11,7 @@ class QueryUrl {
             this.url.searchParams.delete(paramName);
             paramValue.forEach(function(value) {
                 this.url.searchParams.append(paramName, value);
-            });
+            }.bind(this));
         } else if (paramValue != null) {
             // set one value for one parameter
             this.url.searchParams.set(paramName, paramValue);
@@ -19,7 +19,7 @@ class QueryUrl {
             // unset value for multiple parameters
             paramName.forEach(function(name) {
                 this.url.searchParams.delete(name);
-            });
+            }.bind(this));
         } else {
             // unset value for one parameter
             this.url.searchParams.delete(paramName);