diff --git a/classlib/src/main/java/org/teavm/classlib/java/io/TFileOutputStream.java b/classlib/src/main/java/org/teavm/classlib/java/io/TFileOutputStream.java
index 20187534f..30e04bf9e 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/io/TFileOutputStream.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/io/TFileOutputStream.java
@@ -24,7 +24,7 @@ import org.teavm.classlib.fs.VirtualFile;
 import org.teavm.classlib.fs.VirtualFileAccessor;
 
 public class TFileOutputStream extends OutputStream {
-    private static byte[] ONE_BYTE_BUFER = new byte[1];
+    private static final byte[] ONE_BYTE_BUFER = new byte[1];
     private VirtualFileAccessor accessor;
 
     public TFileOutputStream(TFile file) throws FileNotFoundException {