diff --git a/src/main/java/org/apache/commons/fileupload/MultipartStream.java b/src/main/java/org/apache/commons/fileupload/MultipartStream.java
index 9e0cbcd..6b37ac8 100644
--- a/src/main/java/org/apache/commons/fileupload/MultipartStream.java
+++ b/src/main/java/org/apache/commons/fileupload/MultipartStream.java
@@ -319,6 +319,11 @@
             byte[] boundary,
             int bufSize,
             ProgressNotifier pNotifier) {
+
+        if (boundary == null) {
+            throw new IllegalArgumentException("boundary may not be null");
+        }
+
         this.input = input;
         this.bufSize = bufSize;
         this.buffer = new byte[bufSize];
diff --git a/src/test/java/org/apache/commons/fileupload/MultipartStreamTest.java b/src/test/java/org/apache/commons/fileupload/MultipartStreamTest.java
index 195a52a..af708c1 100644
--- a/src/test/java/org/apache/commons/fileupload/MultipartStreamTest.java
+++ b/src/test/java/org/apache/commons/fileupload/MultipartStreamTest.java
@@ -48,6 +48,7 @@
         assertNotNull(ms);
     }
 
+    @SuppressWarnings("unused")
     @Test(expected=IllegalArgumentException.class)
     public void testSmallBuffer() throws Exception {
         final String strData = "foobar";
@@ -55,8 +56,7 @@
         InputStream input = new ByteArrayInputStream(contents);
         byte[] boundary = BOUNDARY_TEXT.getBytes();
         int iBufSize = 1;
-        @SuppressWarnings("unused")
-        MultipartStream ms = new MultipartStream(
+        new MultipartStream(
                 input,
                 boundary,
                 iBufSize,