diff --git a/internal/graphicsdriver/opengl/context_notx.go b/internal/graphicsdriver/opengl/context_notx.go
deleted file mode 100644
index f7d25d04f..000000000
--- a/internal/graphicsdriver/opengl/context_notx.go
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2020 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//go:build android || js || (!freebsd && !linux)
-// +build android js !freebsd,!linux
-
-package opengl
-
-func isPBOAvailable() bool {
-	return true
-}
diff --git a/internal/graphicsdriver/opengl/context_x.go b/internal/graphicsdriver/opengl/context_x.go
deleted file mode 100644
index a202a683d..000000000
--- a/internal/graphicsdriver/opengl/context_x.go
+++ /dev/null
@@ -1,47 +0,0 @@
-// Copyright 2020 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//go:build (freebsd || linux) && !android
-// +build freebsd linux
-// +build !android
-
-package opengl
-
-import (
-	"strings"
-	"sync"
-
-	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl/gl"
-)
-
-var (
-	pboAvailable     = true
-	pboAvailableOnce sync.Once
-)
-
-func isPBOAvailable() bool {
-	pboAvailableOnce.Do(func() {
-		// This must be called after GL context is created.
-		str := gl.RendererDeviceString()
-		tokens := strings.Split(str, " ")
-		if len(tokens) == 0 {
-			return
-		}
-		// Raspbery Pi 4 has an issue around PBO (#1208).
-		if tokens[0] == "V3D" {
-			pboAvailable = false
-		}
-	})
-	return pboAvailable
-}