diff --git a/java/src/com/android/inputmethod/dictionarypack/UpdateHandler.java b/java/src/com/android/inputmethod/dictionarypack/UpdateHandler.java
index 0517bc8..6b32c68 100644
--- a/java/src/com/android/inputmethod/dictionarypack/UpdateHandler.java
+++ b/java/src/com/android/inputmethod/dictionarypack/UpdateHandler.java
@@ -689,8 +689,16 @@
         } else {
             try {
                 final FileChannel sourceChannel = ((FileInputStream) in).getChannel();
-                final FileChannel destinationChannel = ((FileOutputStream) out).getChannel();
-                sourceChannel.transferTo(0, Integer.MAX_VALUE, destinationChannel);
+                try {
+                    final FileChannel destinationChannel = ((FileOutputStream) out).getChannel();
+                    try {
+                        sourceChannel.transferTo(0, Integer.MAX_VALUE, destinationChannel);
+                    } finally {
+                        destinationChannel.close();
+                    }
+                } finally {
+                    sourceChannel.close();
+                }
             } catch (IOException e) {
                 // Can't work with channels, or something went wrong. Copy by hand.
                 DebugLogUtils.l("Won't work");