diff --git a/server.go b/server.go
index 349e5b9..e56a004 100644
--- a/server.go
+++ b/server.go
@@ -98,11 +98,11 @@ func (u *Upgrader) Upgrade(w http.ResponseWriter, r *http.Request, responseHeade
 	}
 
 	if !tokenListContainsValue(r.Header, "Connection", "upgrade") {
-		return u.returnError(w, r, http.StatusBadRequest, "websocket: connection header != upgrade")
+		return u.returnError(w, r, http.StatusBadRequest, "websocket: could not find connection header with token 'upgrade'")
 	}
 
 	if !tokenListContainsValue(r.Header, "Upgrade", "websocket") {
-		return u.returnError(w, r, http.StatusBadRequest, "websocket: upgrade != websocket")
+		return u.returnError(w, r, http.StatusBadRequest, "websocket: could not find upgrade header with token 'websocket'")
 	}
 
 	checkOrigin := u.CheckOrigin