diff --git a/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedOutputStream.java b/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedOutputStream.java
new file mode 100644
index 000000000..e46af5019
--- /dev/null
+++ b/classlib/src/main/java/org/teavm/classlib/java/io/TBufferedOutputStream.java
@@ -0,0 +1,111 @@
+/*
+ *  Copyright 2017 Alexey Andreev.
+ *
+ *  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.
+ */
+
+package org.teavm.classlib.java.io;
+
+public class TBufferedOutputStream extends TFilterOutputStream {
+    protected byte[] buf;
+    protected int count;
+
+    public TBufferedOutputStream(TOutputStream out) {
+        super(out);
+        buf = new byte[8192];
+    }
+
+    public TBufferedOutputStream(TOutputStream out, int size) {
+        super(out);
+        if (size <= 0) {
+            throw new IllegalArgumentException("size must be > 0");
+        }
+        buf = new byte[size];
+    }
+
+    @Override
+    public void flush() throws TIOException {
+        flushInternal();
+        out.flush();
+    }
+
+    @Override
+    public void write(byte[] buffer, int offset, int length) throws TIOException {
+        byte[] internalBuffer = buf;
+
+        if (internalBuffer != null && length >= internalBuffer.length) {
+            flushInternal();
+            out.write(buffer, offset, length);
+            return;
+        }
+
+        if (buffer == null) {
+            throw new NullPointerException("buffer is null");
+        }
+        
+        if (offset < 0 || offset > buffer.length - length) {
+            throw new ArrayIndexOutOfBoundsException("Offset out of bounds: " + offset);
+        
+        }
+        if (length < 0) {
+            throw new ArrayIndexOutOfBoundsException("Length out of bounds: " + length);
+        }
+
+        if (internalBuffer == null) {
+            throw new TIOException();
+        }
+
+        // flush the internal buffer first if we have not enough space left
+        if (length >= (internalBuffer.length - count)) {
+            flushInternal();
+        }
+
+        // the length is always less than (internalBuffer.length - count) here so arraycopy is safe
+        System.arraycopy(buffer, offset, internalBuffer, count, length);
+        count += length;
+    }
+
+    @Override
+    public void close() throws TIOException {
+        if (buf == null) {
+            return;
+        }
+        
+        try {
+            super.close();
+        } finally {
+            buf = null;
+        }
+    }
+
+    @Override
+    public void write(int oneByte) throws TIOException {
+        byte[] internalBuffer = buf;
+        if (internalBuffer == null) {
+            throw new TIOException();
+        }
+
+        if (count == internalBuffer.length) {
+            out.write(internalBuffer, 0, count);
+            count = 0;
+        }
+        internalBuffer[count++] = (byte) oneByte;
+    }
+
+    private void flushInternal() throws TIOException {
+        if (count > 0) {
+            out.write(buf, 0, count);
+            count = 0;
+        }
+    }
+}