diff --git a/v2/protocol/http/protocol.go b/v2/protocol/http/protocol.go
index dba6fd7ba..7ee3b8fe1 100644
--- a/v2/protocol/http/protocol.go
+++ b/v2/protocol/http/protocol.go
@@ -102,7 +102,10 @@ func New(opts ...Option) (*Protocol, error) {
 	}
 
 	if p.Client == nil {
-		p.Client = http.DefaultClient
+		// This is how http.DefaultClient is initialized. We do not just use
+		// that because when WithRoundTripper is used, it will change the client's
+		// transport, which would cause that transport to be used process-wide.
+		p.Client = &http.Client{}
 	}
 
 	if p.roundTripper != nil {