diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/ImportExportOperation.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/ImportExportOperation.java
index 0bd8ada5a..f42053bad 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/ImportExportOperation.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/operations/ImportExportOperation.java
@@ -46,6 +46,7 @@ import org.sufficientlysecure.keychain.util.FileHelper;
 import org.sufficientlysecure.keychain.util.Log;
 import org.sufficientlysecure.keychain.util.ProgressScaler;
 
+import java.io.BufferedOutputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -289,6 +290,10 @@ public class ImportExportOperation extends BaseOperation {
         }
         */
 
+        if ( ! BufferedOutputStream.class.isInstance(outStream)) {
+            outStream = new BufferedOutputStream(outStream);
+        }
+
         int okSecret = 0, okPublic = 0, progress = 0;
 
         try {