diff --git a/session/session.go b/session/session.go
index 3aa53936..ca530585 100644
--- a/session/session.go
+++ b/session/session.go
@@ -49,6 +49,10 @@ func (c *Caps) ProcessExtensionCapabilities() {
 
 	if c.ExtensionCapabilities != nil {
 		mergo.Merge(c, *c.ExtensionCapabilities, mergo.WithOverride) //We probably need to handle returned error
+
+		//According to Selenium standard vendor-specific capabilities for
+		//intermediary node should not be proxied to endpoint node
+		c.ExtensionCapabilities = nil
 	}
 }