diff --git a/oauth2_test.go b/oauth2_test.go
index 14f041d..4937901 100644
--- a/oauth2_test.go
+++ b/oauth2_test.go
@@ -453,18 +453,14 @@ func TestRefreshToken_RefreshTokenReplacement(t *testing.T) {
 	}))
 	defer ts.Close()
 	conf := newConf(ts.URL)
-	tkr := &tokenRefresher{
-		conf:         conf,
-		ctx:          context.Background(),
-		refreshToken: "OLD_REFRESH_TOKEN",
-	}
+	tkr := conf.TokenSource(context.Background(), &Token{RefreshToken: "OLD_REFRESH_TOKEN"})
 	tk, err := tkr.Token()
 	if err != nil {
 		t.Errorf("got err = %v; want none", err)
 		return
 	}
-	if tk.RefreshToken != tkr.refreshToken {
-		t.Errorf("tokenRefresher.refresh_token = %q; want %q", tkr.refreshToken, tk.RefreshToken)
+	if want := "NEW_REFRESH_TOKEN"; tk.RefreshToken != want {
+		t.Errorf("RefreshToken = %q; want %q", tk.RefreshToken, want)
 	}
 }
 
@@ -477,17 +473,13 @@ func TestRefreshToken_RefreshTokenPreservation(t *testing.T) {
 	defer ts.Close()
 	conf := newConf(ts.URL)
 	const oldRefreshToken = "OLD_REFRESH_TOKEN"
-	tkr := &tokenRefresher{
-		conf:         conf,
-		ctx:          context.Background(),
-		refreshToken: oldRefreshToken,
-	}
-	_, err := tkr.Token()
+	tkr := conf.TokenSource(context.Background(), &Token{RefreshToken: oldRefreshToken})
+	tk, err := tkr.Token()
 	if err != nil {
 		t.Fatalf("got err = %v; want none", err)
 	}
-	if tkr.refreshToken != oldRefreshToken {
-		t.Errorf("tokenRefresher.refreshToken = %q; want %q", tkr.refreshToken, oldRefreshToken)
+	if tk.RefreshToken != oldRefreshToken {
+		t.Errorf("RefreshToken = %q; want %q", tk.RefreshToken, oldRefreshToken)
 	}
 }