diff --git a/classpath/java/io/FileOutputStream.java b/classpath/java/io/FileOutputStream.java
index 8732004e7..f5518d797 100644
--- a/classpath/java/io/FileOutputStream.java
+++ b/classpath/java/io/FileOutputStream.java
@@ -52,7 +52,7 @@ public void write(byte[] b, int offset, int length) throws IOException {
       throw new NullPointerException();
     }
 
-    if (offset < 0 || offset + length > b.length) {
+    if (offset < 0 || length < 0 || length > b.length || offset > b.length - length) {
       throw new ArrayIndexOutOfBoundsException();
     }