diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/TemporaryBuffer.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/TemporaryBuffer.java
index 006c3c0a0..3719bf794 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/TemporaryBuffer.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/TemporaryBuffer.java
@@ -44,6 +44,7 @@
 
 package org.eclipse.jgit.util;
 
+import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -435,7 +436,7 @@ public LocalFile(final File directory, final int inCoreLimit) {
 
 		protected OutputStream overflow() throws IOException {
 			onDiskFile = File.createTempFile("jgit_", ".buf", directory); //$NON-NLS-1$ //$NON-NLS-2$
-			return new FileOutputStream(onDiskFile);
+			return new BufferedOutputStream(new FileOutputStream(onDiskFile));
 		}
 
 		public long length() {