diff --git a/config/config.go b/config/config.go
index 37c0888f3f0..90b38c62510 100644
--- a/config/config.go
+++ b/config/config.go
@@ -682,7 +682,7 @@ func SetupViper(v *viper.Viper, filename string) {
 	v.SetDefault("adapters.sonobi.endpoint", "https://apex.go.sonobi.com/prebid?partnerid=71d9d3d8af")
 	v.SetDefault("adapters.unruly.endpoint", "http://targeting.unrulymedia.com/openrtb/2.2")
 	v.SetDefault("adapters.vrtcal.endpoint", "http://rtb.vrtcal.com/bidder_prebid.vap?ssp=1804")
-	v.SetDefault("adapters.yieldmo.endpoint", "http://ads.yieldmo.com/exchange/prebid-server")
+	v.SetDefault("adapters.yieldmo.endpoint", "https://ads.yieldmo.com/exchange/prebid-server")
 	v.SetDefault("adapters.gamoshi.endpoint", "https://rtb.gamoshi.io")
 	v.SetDefault("adapters.gamma.endpoint", "https://hb.gammaplatform.com/adx/request/")
 	v.SetDefault("adapters.mgid.endpoint", "https://prebid.mgid.com/prebid/")