diff --git a/src/prebid.js b/src/prebid.js
index 855d53d7de0..5dec6b86336 100644
--- a/src/prebid.js
+++ b/src/prebid.js
@@ -554,13 +554,12 @@ $$PREBID_GLOBAL$$.requestBids = hook('async', function ({ bidsBackHandler, timeo
 
   logInfo('Invoking $$PREBID_GLOBAL$$.requestBids', arguments);
 
-  let _s2sConfigs = [];
   const s2sBidders = [];
-  config.getConfig('s2sConfig', config => {
-    if (config && config.s2sConfig) {
-      _s2sConfigs = Array.isArray(config.s2sConfig) ? config.s2sConfig : [config.s2sConfig];
-    }
-  });
+  let _s2sConfigs = config.getConfig('s2sConfig') || [];
+
+  if (!Array.isArray(_s2sConfigs)) {
+    _s2sConfigs = [_s2sConfigs];
+  }
 
   _s2sConfigs.forEach(s2sConfig => {
     s2sBidders.push(...s2sConfig.bidders);