diff --git a/src/currencyservice/server.js b/src/currencyservice/server.js
index 1669cd9..ed6b099 100644
--- a/src/currencyservice/server.js
+++ b/src/currencyservice/server.js
@@ -77,7 +77,7 @@ function _getCurrencyData (callback) {
   if (hour > 8 && hour < 17) {
     delay = 100; // add 100ms slowdown
   }
-  setTimeout(callback(data), delay);
+  setTimeout(() => callback(data), delay);
 }
 
 /**